M. Nguyen, An Hoang-Thuy Nguyen, Jiyong Yim, Anh-Duy Nguyen, Mingyu Kim, Jeonghan Kim, Jong-hyun Beak, R. Choi
Individual charge traps in the gate stack of gate-all-around field-effect-transistors have been identified from their random telegraph noise (RTN) characteristics in the time and frequency domains. The energy level and depth location of the corresponding charge traps were extracted from capture/emission time constant and corner frequency. The charge traps were determined to be the excited states of oxygen vacancies in the dielectric located 3 nm away from the interface. Both the time domain and frequency domain RTN measurements lead to an identical result.
{"title":"Electrical characterization of gate stack charge traps in floating body gate-all-around field-effect-transistors","authors":"M. Nguyen, An Hoang-Thuy Nguyen, Jiyong Yim, Anh-Duy Nguyen, Mingyu Kim, Jeonghan Kim, Jong-hyun Beak, R. Choi","doi":"10.1116/6.0000906","DOIUrl":"https://doi.org/10.1116/6.0000906","url":null,"abstract":"Individual charge traps in the gate stack of gate-all-around field-effect-transistors have been identified from their random telegraph noise (RTN) characteristics in the time and frequency domains. The energy level and depth location of the corresponding charge traps were extracted from capture/emission time constant and corner frequency. The charge traps were determined to be the excited states of oxygen vacancies in the dielectric located 3 nm away from the interface. Both the time domain and frequency domain RTN measurements lead to an identical result.","PeriodicalId":17652,"journal":{"name":"Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75343136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Taiyu Okatani, Yuichi Sato, K. Imai, K. Hane, Y. Kanamori
In silicon photonics, silicon microdisk resonators with movable waveguides driven by electrostatic comb-drive actuators have been used as wavelength-selective switches. However, the sidewall roughness of silicon waveguides formed by the etching process is the main cause of optical loss in such devices, which leads to the deterioration of the wavelength selectivity. In this study, we fabricated a silicon microdisk resonator with a movable waveguide and performed a hydrogen annealing treatment as a postprocessing step to remove the sidewall roughness. By using scanning electron microscopy, a reduction in sidewall roughness was confirmed following the hydrogen annealing treatment. Then, the extinction ratio at the through port was evaluated while changing the gap between the microdisk and the movable waveguide. A dip in the extinction ratio was observed at the resonant wavelength while decreasing the gap, which indicated that the fabricated device successfully functioned as a wavelength-selective switch. Due to the hydrogen annealing treatment, the quality factor of the dip increased from 7102 to 37 402. These results show that the hydrogen annealing treatment can be used as a postprocessing step and is helpful for improving the wavelength selectivity of silicon photonic wavelength-selective switches.
{"title":"Improvement of silicon microdisk resonators with movable waveguides by hydrogen annealing treatment","authors":"Taiyu Okatani, Yuichi Sato, K. Imai, K. Hane, Y. Kanamori","doi":"10.1116/6.0000971","DOIUrl":"https://doi.org/10.1116/6.0000971","url":null,"abstract":"In silicon photonics, silicon microdisk resonators with movable waveguides driven by electrostatic comb-drive actuators have been used as wavelength-selective switches. However, the sidewall roughness of silicon waveguides formed by the etching process is the main cause of optical loss in such devices, which leads to the deterioration of the wavelength selectivity. In this study, we fabricated a silicon microdisk resonator with a movable waveguide and performed a hydrogen annealing treatment as a postprocessing step to remove the sidewall roughness. By using scanning electron microscopy, a reduction in sidewall roughness was confirmed following the hydrogen annealing treatment. Then, the extinction ratio at the through port was evaluated while changing the gap between the microdisk and the movable waveguide. A dip in the extinction ratio was observed at the resonant wavelength while decreasing the gap, which indicated that the fabricated device successfully functioned as a wavelength-selective switch. Due to the hydrogen annealing treatment, the quality factor of the dip increased from 7102 to 37 402. These results show that the hydrogen annealing treatment can be used as a postprocessing step and is helpful for improving the wavelength selectivity of silicon photonic wavelength-selective switches.","PeriodicalId":17652,"journal":{"name":"Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81330208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The outgassing rates of various ceramic materials were systematically investigated. This paper intercompares the most relevant ceramic material classes used in vacuum technology, namely, oxide (five different types investigated) and non-oxide based ceramics, including nitrides (four different types) and carbides (three different types). For this purpose, the Outgassing Measurement Apparatus, which uses the difference method, was applied. Besides time, also, temperature dependence of outgassing was studied to check whether a previous heat treatment of the ceramics is necessary. Additionally, the outgassing species were qualitatively determined by a quadrupole mass spectrometer. In total, relatively large differences were found between the investigated ceramic materials for their initial outgassing rates as well as for their behavior at elevated temperatures. All investigated types of carbide ceramics showed very low outgassing rates of less than 3 × 10−8 Pa m3/(s m2) after 100 h at room temperature, whereas rather high outgassing rates of about 10−5 Pa m3/(s m2) were found for magnesia as well as the tested nitride ceramic types. Thus, depending on the ceramic material, a heat treatment is strongly recommended before use in ultrahigh vacuum applications.
系统地研究了各种陶瓷材料的放气速率。本文比较了真空技术中使用的最相关的陶瓷材料类别，即氧化物(研究了五种不同类型)和非氧化物陶瓷，包括氮化物(四种不同类型)和碳化物(三种不同类型)。为此，采用差分法的放气测量仪。除时间外，还研究了除气的温度依赖性，以确定是否有必要对陶瓷进行预先热处理。另外，用四极杆质谱仪对出气物质进行了定性测定。总的来说，在所研究的陶瓷材料之间发现了相对较大的差异，它们的初始放气速率以及它们在高温下的行为。所有类型的碳化物陶瓷在室温下100小时的放气率都低于3 × 10−8 Pa m3/(s m2)，而氧化镁和所测试的氮化陶瓷类型的放气率相当高，约为10−5 Pa m3/(s m2)。因此，根据陶瓷材料的不同，强烈建议在超高真空应用中使用之前进行热处理。
{"title":"Systematic study of the outgassing behavior of different ceramic materials","authors":"K. Battes, C. Day, V. Hauer","doi":"10.1116/6.0000954","DOIUrl":"https://doi.org/10.1116/6.0000954","url":null,"abstract":"The outgassing rates of various ceramic materials were systematically investigated. This paper intercompares the most relevant ceramic material classes used in vacuum technology, namely, oxide (five different types investigated) and non-oxide based ceramics, including nitrides (four different types) and carbides (three different types). For this purpose, the Outgassing Measurement Apparatus, which uses the difference method, was applied. Besides time, also, temperature dependence of outgassing was studied to check whether a previous heat treatment of the ceramics is necessary. Additionally, the outgassing species were qualitatively determined by a quadrupole mass spectrometer. In total, relatively large differences were found between the investigated ceramic materials for their initial outgassing rates as well as for their behavior at elevated temperatures. All investigated types of carbide ceramics showed very low outgassing rates of less than 3 × 10−8 Pa m3/(s m2) after 100 h at room temperature, whereas rather high outgassing rates of about 10−5 Pa m3/(s m2) were found for magnesia as well as the tested nitride ceramic types. Thus, depending on the ceramic material, a heat treatment is strongly recommended before use in ultrahigh vacuum applications.","PeriodicalId":17652,"journal":{"name":"Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87368762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hole-transport material-free perovskite solar cells were prepared by utilizing a spin-coating method. To optimize the dropping conditions of the toluene as an antisolvent in the nitrogen atmosphere, the CH3NH3PbI3/TiO2/fluorine-doped tin oxide (FTO)/glass specimen consisted of a high-density tissue, and crystal faults such as voids and cracks were not observed on its surface. By controlling the thickness of the mesoporous TiO2 layer with the rotation speed (x) of a spin coater, it was speculated that the thicker mesoporous TiO2 layer enables not only an efficient electron extraction from the CH3NH3PbI3 perovskite layer but also a smooth transition of electrons to the FTO electrode. Moreover, the precursor solution for CH3NH3PbI3 perovskite crystals was optimized for its molar concentration (y). The energy conversion efficiency (η) gradually increased from η = 5.8% to 9.6% with an increase in y to 2.6 M above which it decreased. The reason to obtain a superior energy conversion efficiency is so that the larger interface between the mesoporous TiO2 and perovskite layers is able to extract photoexcited electrons effectively. The above facts show for that the perovskite solar cells that have a larger area are synthesized with good reproducibility.
{"title":"Behavior of photoexcited electrons in hole-transport material-free perovskite solar cells","authors":"M. Hirai, Y. Takagi, N. Fujita","doi":"10.1116/6.0000913","DOIUrl":"https://doi.org/10.1116/6.0000913","url":null,"abstract":"Hole-transport material-free perovskite solar cells were prepared by utilizing a spin-coating method. To optimize the dropping conditions of the toluene as an antisolvent in the nitrogen atmosphere, the CH3NH3PbI3/TiO2/fluorine-doped tin oxide (FTO)/glass specimen consisted of a high-density tissue, and crystal faults such as voids and cracks were not observed on its surface. By controlling the thickness of the mesoporous TiO2 layer with the rotation speed (x) of a spin coater, it was speculated that the thicker mesoporous TiO2 layer enables not only an efficient electron extraction from the CH3NH3PbI3 perovskite layer but also a smooth transition of electrons to the FTO electrode. Moreover, the precursor solution for CH3NH3PbI3 perovskite crystals was optimized for its molar concentration (y). The energy conversion efficiency (η) gradually increased from η = 5.8% to 9.6% with an increase in y to 2.6 M above which it decreased. The reason to obtain a superior energy conversion efficiency is so that the larger interface between the mesoporous TiO2 and perovskite layers is able to extract photoexcited electrons effectively. The above facts show for that the perovskite solar cells that have a larger area are synthesized with good reproducibility.","PeriodicalId":17652,"journal":{"name":"Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84784520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. F. Dall’Agnol, S. Filippov, E. O. Popov, A. G. Kolosko, T. A. de Assis
Theoretical analysis of field electron emission must consider many parameters, one of the most critical being the field enhancement factor (FEF). In a single tip form, the FEF can vary several orders of magnitude and depends only on the system geometry, when the gap length between the emitter and counter-electrode is much greater than the height of the emitter. In this work, we determine very accurate analytical expressions for the FEF of five emitters with various shapes, which are often considered in the literature: Ellipsoidal, Hemisphere-on-Cylindrical post, Hemisphere-on-Orthogonal cone, Paraboloidal, and Hyperboloidal. We map the FEF as a function of the aspect ratio with an error smaller than 2% to serve as a quick reference database. Additionally, we calculate the electric field distribution over the emitters, which can give an insight into the effective notional emission area and the influence of the emitter’s base.
{"title":"Determining the field enhancement factors of various field electron emitters with high numerical accuracy","authors":"F. F. Dall’Agnol, S. Filippov, E. O. Popov, A. G. Kolosko, T. A. de Assis","doi":"10.1116/6.0000949","DOIUrl":"https://doi.org/10.1116/6.0000949","url":null,"abstract":"Theoretical analysis of field electron emission must consider many parameters, one of the most critical being the field enhancement factor (FEF). In a single tip form, the FEF can vary several orders of magnitude and depends only on the system geometry, when the gap length between the emitter and counter-electrode is much greater than the height of the emitter. In this work, we determine very accurate analytical expressions for the FEF of five emitters with various shapes, which are often considered in the literature: Ellipsoidal, Hemisphere-on-Cylindrical post, Hemisphere-on-Orthogonal cone, Paraboloidal, and Hyperboloidal. We map the FEF as a function of the aspect ratio with an error smaller than 2% to serve as a quick reference database. Additionally, we calculate the electric field distribution over the emitters, which can give an insight into the effective notional emission area and the influence of the emitter’s base.","PeriodicalId":17652,"journal":{"name":"Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83900179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shunfu Xu, Wei-hui Liu, Ziliang Zhu, Chun Li, G. Yuan
First-principles calculations are used to investigate electronic and field emission characteristics of (5, 5) capped BeO nanotubes (BeONTs), which indicate that their emission currents under external electric fields are close to those of carbon nanotubes, and decagons on their apexes are the most probable positions for electron emission. In addition, work functions of the (5, 5) BeONTs decrease linearly with applied electric fields. The remarkable influence of lithium adsorption on their field emission characteristics is also investigated. Their work functions decline distinctly after lithium adsorption, while the emission currents have been improved by more than one order of magnitude. Moreover, there is a polynomial relationship between the total currents and the external fields.
{"title":"Electronic structure and field emission characteristics of a new kind of BeO nanotubes: A first-principles study","authors":"Shunfu Xu, Wei-hui Liu, Ziliang Zhu, Chun Li, G. Yuan","doi":"10.1116/6.0000945","DOIUrl":"https://doi.org/10.1116/6.0000945","url":null,"abstract":"First-principles calculations are used to investigate electronic and field emission characteristics of (5, 5) capped BeO nanotubes (BeONTs), which indicate that their emission currents under external electric fields are close to those of carbon nanotubes, and decagons on their apexes are the most probable positions for electron emission. In addition, work functions of the (5, 5) BeONTs decrease linearly with applied electric fields. The remarkable influence of lithium adsorption on their field emission characteristics is also investigated. Their work functions decline distinctly after lithium adsorption, while the emission currents have been improved by more than one order of magnitude. Moreover, there is a polynomial relationship between the total currents and the external fields.","PeriodicalId":17652,"journal":{"name":"Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75332951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yigang Wang, Wenli Zhang, Sihui Wang, Wei Wei, Jian Fang, B. Zhu, Yong Wang
Electron cloud is a persistent problem in operating modern accelerators. It might be eliminated by reducing the secondary electron yield (SEY), which is a property of the material of vacuum chambers. In the present study, the SEYs of oxygen-free copper samples are dramatically mitigated by grooving their surfaces with a laser-etching technique. Such mitigation is realized by trapping incident primary electrons and their induced secondary electrons in the grooves. The SEYs of the laser-etched samples are dependent on the geometrical characteristics of the grooves and the incident angles of the primary electrons, i.e., reducing the incident angle can lead to a reduction in the SEY. Electron bombardment of the grooved surface with an electron dose of 2 × 10−2 C mm−2 will further reduce its maximum SEY from 1.15 to 0.98, which might be attributed to the formation of Cu2O and graphite-like C—C bonds and the removal of surface contaminants.
电子云是现代加速器运行中一个长期存在的问题。可以通过降低二次电子产率(SEY)来消除它，这是真空室材料的特性。在本研究中，通过激光蚀刻技术在无氧铜样品表面刻槽，可以显著减轻无氧铜样品的SEYs。这种减缓是通过在凹槽中捕获入射的初级电子及其诱导的次级电子来实现的。激光蚀刻样品的入射光强取决于凹槽的几何特征和一次电子的入射角，即减小入射角可以导致入射光强的减小。以2 × 10−2 C mm−2的电子剂量轰击凹槽表面，将其最大SEY从1.15进一步降低到0.98，这可能是由于Cu2O和石墨样C - C键的形成以及表面污染物的去除。
{"title":"Influence of primary electron incident angle and electron bombardment on the secondary electron yield of laser-treated copper","authors":"Yigang Wang, Wenli Zhang, Sihui Wang, Wei Wei, Jian Fang, B. Zhu, Yong Wang","doi":"10.1116/6.0000952","DOIUrl":"https://doi.org/10.1116/6.0000952","url":null,"abstract":"Electron cloud is a persistent problem in operating modern accelerators. It might be eliminated by reducing the secondary electron yield (SEY), which is a property of the material of vacuum chambers. In the present study, the SEYs of oxygen-free copper samples are dramatically mitigated by grooving their surfaces with a laser-etching technique. Such mitigation is realized by trapping incident primary electrons and their induced secondary electrons in the grooves. The SEYs of the laser-etched samples are dependent on the geometrical characteristics of the grooves and the incident angles of the primary electrons, i.e., reducing the incident angle can lead to a reduction in the SEY. Electron bombardment of the grooved surface with an electron dose of 2 × 10−2 C mm−2 will further reduce its maximum SEY from 1.15 to 0.98, which might be attributed to the formation of Cu2O and graphite-like C—C bonds and the removal of surface contaminants.","PeriodicalId":17652,"journal":{"name":"Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85237177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Angle, A. Palczewski, C. Reece, F. Stevie, M. Kelley
Accurate secondary ion mass spectroscopy measurement of nitrogen in niobium relies on the use of closely equivalent standards, made by ion implantation, to convert nitrogen signal intensity to nitrogen content by determination of relative sensitivity factors (RSFs). Accurate RSF values for ppm-range nitrogen contents are increasingly critical, as more precision is sought in processes for next-generation superconducting radiofrequency (SRF) accelerator cavities. Factors influencing RSF value measurements were investigated with the aim of reliably attaining better than 10% accuracy in nitrogen concentrations at various depths into the bulk. This has been accomplished for materials typical of SRF cavities at the cost of increased attention to all aspects.
{"title":"Advances in secondary ion mass spectrometry for N-doped niobium","authors":"J. Angle, A. Palczewski, C. Reece, F. Stevie, M. Kelley","doi":"10.1116/6.0000848","DOIUrl":"https://doi.org/10.1116/6.0000848","url":null,"abstract":"Accurate secondary ion mass spectroscopy measurement of nitrogen in niobium relies on the use of closely equivalent standards, made by ion implantation, to convert nitrogen signal intensity to nitrogen content by determination of relative sensitivity factors (RSFs). Accurate RSF values for ppm-range nitrogen contents are increasingly critical, as more precision is sought in processes for next-generation superconducting radiofrequency (SRF) accelerator cavities. Factors influencing RSF value measurements were investigated with the aim of reliably attaining better than 10% accuracy in nitrogen concentrations at various depths into the bulk. This has been accomplished for materials typical of SRF cavities at the cost of increased attention to all aspects.","PeriodicalId":17652,"journal":{"name":"Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90065204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Edler, A. Schels, J. Biba, W. Hansch, M. Bachmann, F. Düsberg, Marinus Werber, C. Langer, M. Meyer, David von Bergen, A. Pahlke
{"title":"Publisher’s Note: “Silicon field emitters fabricated by dicing-saw and wet-chemical-etching” [J. Vac. Sci. Technol. B 39, 013205 (2021)]","authors":"S. Edler, A. Schels, J. Biba, W. Hansch, M. Bachmann, F. Düsberg, Marinus Werber, C. Langer, M. Meyer, David von Bergen, A. Pahlke","doi":"10.1116/6.0000974","DOIUrl":"https://doi.org/10.1116/6.0000974","url":null,"abstract":"","PeriodicalId":17652,"journal":{"name":"Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89815870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Keith Hernandez, A. Press, M. Goeckner, L. Overzet
Phase resolved optical emission spectroscopy (PROES) measurements were combined with measurements of the optical emission intensity (OEI) and electrical characteristics (RF current and voltage, power, and DC bias voltage) as a function of time during the re-ignition of Ar plasmas pulsed at 100 Hz and 10 kHz. The OEI exhibits a large overshoot at the 100 Hz pulsing rate even though no such overshoot is present in any of the electrical characteristics. The OEI overshoot occurs at a point in time when the RF power, voltage, DC bias voltage, and electron density are all smaller than they become later in the glow. PROES measurements in combination with the time resolved electrical characteristics indicate that the heating mechanism for the electrons changes during the time of the overshoot in the OEI from stochastic heating to a combination of stochastic and ohmic heating. This combination appears to enable a more efficient transfer of the electrical energy into the electrons.
{"title":"Optical emission intensity overshoot and electron heating mechanisms during the re-ignition of pulsed capacitively coupled Ar plasmas","authors":"Keith Hernandez, A. Press, M. Goeckner, L. Overzet","doi":"10.1116/6.0000679","DOIUrl":"https://doi.org/10.1116/6.0000679","url":null,"abstract":"Phase resolved optical emission spectroscopy (PROES) measurements were combined with measurements of the optical emission intensity (OEI) and electrical characteristics (RF current and voltage, power, and DC bias voltage) as a function of time during the re-ignition of Ar plasmas pulsed at 100 Hz and 10 kHz. The OEI exhibits a large overshoot at the 100 Hz pulsing rate even though no such overshoot is present in any of the electrical characteristics. The OEI overshoot occurs at a point in time when the RF power, voltage, DC bias voltage, and electron density are all smaller than they become later in the glow. PROES measurements in combination with the time resolved electrical characteristics indicate that the heating mechanism for the electrons changes during the time of the overshoot in the OEI from stochastic heating to a combination of stochastic and ohmic heating. This combination appears to enable a more efficient transfer of the electrical energy into the electrons.","PeriodicalId":17652,"journal":{"name":"Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86352332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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