Sylvester Amoah, H. Stanchu, G. Abernathy, Serhii Kryvyi, F. D. de Oliveira, Yuriy I. Mazur, Shangda Li, Shang Liu, Jifeng Liu, Wei Du, Baohua Li, Gregory J. Salamo, Shui-Qing Yu
Ion implantation is widely used in the complementary metal–oxide–semiconductor process, which stimulates to study its role for doping control in rapidly emerging group IV Ge1−xSnx materials. We tested the impact of As and B implantation and of subsequent rapid thermal annealing (RTA) on the damage formation and healing of the Ge1−xSnx lattice. Ion implantation was done at 30, 40, and 150 keV and with various doses. The implantation profiles were confirmed using secondary ion mass spectrometry. X-ray diffraction in combination with Raman and photoluminescence spectroscopies indicated notable crystal damage with the increase of the implantation dose and energy. Significant damage recovery was confirmed after RTA treatment at 300 °C and to a larger extent at 400 °C for a Ge1−xSnx sample with Sn content less than 11%. A GeSn NP diode was fabricated after ion implantation. The device showed rectifying current-voltage characteristics with maximum responsivity and detectivity of 1.29 × 10−3 A/W and 3.0 × 106 cm (Hz)1/2/W at 77 K, respectively.
离子注入在互补金属-氧化物-半导体工艺中得到广泛应用，这促使我们研究离子注入在快速出现的第四组 Ge1-xSnx 材料中的掺杂控制作用。我们测试了 As 和 B 植入以及随后的快速热退火（RTA）对 Ge1-xSnx 晶格损伤形成和愈合的影响。离子植入在 30、40 和 150 keV 下以不同剂量进行。使用二次离子质谱法确认了植入曲线。X 射线衍射结合拉曼光谱和光致发光光谱显示，随着植入剂量和能量的增加，晶体受到了明显的损坏。对于锡含量小于 11% 的 Ge1-xSnx 样品，在 300 °C 下进行 RTA 处理后证实了明显的损伤恢复，在 400 °C 下损伤恢复程度更大。离子注入后，制造出了一个 GeSn NP 二极管。该器件具有整流电流-电压特性，在 77 K 时的最大响应率和检测率分别为 1.29 × 10-3 A/W 和 3.0 × 106 cm (Hz)1/2/W。
{"title":"Effects of ion implantation with arsenic and boron in germanium-tin layers","authors":"Sylvester Amoah, H. Stanchu, G. Abernathy, Serhii Kryvyi, F. D. de Oliveira, Yuriy I. Mazur, Shangda Li, Shang Liu, Jifeng Liu, Wei Du, Baohua Li, Gregory J. Salamo, Shui-Qing Yu","doi":"10.1116/6.0003565","DOIUrl":"https://doi.org/10.1116/6.0003565","url":null,"abstract":"Ion implantation is widely used in the complementary metal–oxide–semiconductor process, which stimulates to study its role for doping control in rapidly emerging group IV Ge1−xSnx materials. We tested the impact of As and B implantation and of subsequent rapid thermal annealing (RTA) on the damage formation and healing of the Ge1−xSnx lattice. Ion implantation was done at 30, 40, and 150 keV and with various doses. The implantation profiles were confirmed using secondary ion mass spectrometry. X-ray diffraction in combination with Raman and photoluminescence spectroscopies indicated notable crystal damage with the increase of the implantation dose and energy. Significant damage recovery was confirmed after RTA treatment at 300 °C and to a larger extent at 400 °C for a Ge1−xSnx sample with Sn content less than 11%. A GeSn NP diode was fabricated after ion implantation. The device showed rectifying current-voltage characteristics with maximum responsivity and detectivity of 1.29 × 10−3 A/W and 3.0 × 106 cm (Hz)1/2/W at 77 K, respectively.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"14 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140727029","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}
Xiaoli Zhu, Zihao Wang, Chenxu Zhu, Jiashi Shen, Babak Shokouhi, H. Ekinci, Bo Cui
Inductively coupled plasma etching of silicon nanostructures for metalens applications using a continuous, multi-step C4F8/SF6 plasma was investigated to achieve high aspect ratio (HAR) features down to tens of nanometers with smooth sidewalls. In the process, the ion bombardment and the free radical transport significantly change among HAR nanostructures as the etching progresses, posing challenges to profile control. With a fixed gas ratio, a change in the profile angle occurs at a depth of approximately 400 nm, transitioning from a positive taper to a negative one. Additionally, a wave-like pillar profile is produced when using three separate (i.e., plasma turned off after each step) etching processes with varying gas ratios. To optimize passivation and etching, we adopt a three-step C4F8/SF6 plasma etching process with varying gas ratios at different etching depths. By keeping the plasma on after each step, the continuous, three-step process provides more flexibility for tuning the etching of HAR nanostructures with smooth and vertical profiles. Metalens nanostructures with 71 nm diameter and 1 μm height were created using the appropriate gas ratio. The feature size variation is less than 10 nm. This proposed continuous, multi-step process improves the controllability of silicon etching in C4F8/SF6 plasma, facilitating the nanofabrication of silicon metalens and other nanodevices.
{"title":"Multi-step plasma etching of high aspect ratio silicon nanostructures for metalens fabrication","authors":"Xiaoli Zhu, Zihao Wang, Chenxu Zhu, Jiashi Shen, Babak Shokouhi, H. Ekinci, Bo Cui","doi":"10.1116/6.0003429","DOIUrl":"https://doi.org/10.1116/6.0003429","url":null,"abstract":"Inductively coupled plasma etching of silicon nanostructures for metalens applications using a continuous, multi-step C4F8/SF6 plasma was investigated to achieve high aspect ratio (HAR) features down to tens of nanometers with smooth sidewalls. In the process, the ion bombardment and the free radical transport significantly change among HAR nanostructures as the etching progresses, posing challenges to profile control. With a fixed gas ratio, a change in the profile angle occurs at a depth of approximately 400 nm, transitioning from a positive taper to a negative one. Additionally, a wave-like pillar profile is produced when using three separate (i.e., plasma turned off after each step) etching processes with varying gas ratios. To optimize passivation and etching, we adopt a three-step C4F8/SF6 plasma etching process with varying gas ratios at different etching depths. By keeping the plasma on after each step, the continuous, three-step process provides more flexibility for tuning the etching of HAR nanostructures with smooth and vertical profiles. Metalens nanostructures with 71 nm diameter and 1 μm height were created using the appropriate gas ratio. The feature size variation is less than 10 nm. This proposed continuous, multi-step process improves the controllability of silicon etching in C4F8/SF6 plasma, facilitating the nanofabrication of silicon metalens and other nanodevices.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"34 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140728064","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}
Jaydip Sawant, Ketan Bhotkar, Y. Yu, Kyu Chang Park
In x-ray imaging, high resolution is essential, particularly in sectors such as medical and industries where the need for nondestructive defect detection is required. Previous research has shown that altering beam design and the number of gates offset holes has an impact on focal spot size (FSS). However, the specific effects of beam size and offset size were not thoroughly assessed. In the present study, the influence of beam size and gate offset size was evaluated by utilizing a cold cathode electron beam. Various beam sizes were employed to achieve a small FSS, and subsequently, the smallest beam was utilized to examine the impact of gate offset size. In doing so, the smallest FSS of 0.25 mm vertical and 0.33 mm horizontal was attained without the utilization of any additional focusing lens. This illustrates that by adjusting the beam size and gate offset size, it is possible to attain a small FSS, facilitating the development of an economically viable x-ray imaging beam.
在 X 射线成像中，高分辨率至关重要，尤其是在需要进行无损缺陷检测的医疗和工业等领域。以往的研究表明，改变光束设计和栅极偏移孔的数量会影响焦斑尺寸（FSS）。然而，光束尺寸和偏移尺寸的具体影响尚未得到全面评估。本研究利用冷阴极电子束评估了光束尺寸和栅极偏移尺寸的影响。为了实现小型 FSS，我们采用了不同的光束尺寸，然后利用最小的光束来检验栅极偏移尺寸的影响。这样，在不使用任何额外聚焦透镜的情况下，实现了垂直方向 0.25 毫米、水平方向 0.33 毫米的最小 FSS。这说明，通过调整光束尺寸和栅极偏移尺寸，可以获得较小的 FSS，从而促进开发出经济可行的 X 射线成像光束。
{"title":"Effect of beam and gate offset size on x-ray focal spot resolution of a cold cathode electron beam","authors":"Jaydip Sawant, Ketan Bhotkar, Y. Yu, Kyu Chang Park","doi":"10.1116/6.0003390","DOIUrl":"https://doi.org/10.1116/6.0003390","url":null,"abstract":"In x-ray imaging, high resolution is essential, particularly in sectors such as medical and industries where the need for nondestructive defect detection is required. Previous research has shown that altering beam design and the number of gates offset holes has an impact on focal spot size (FSS). However, the specific effects of beam size and offset size were not thoroughly assessed. In the present study, the influence of beam size and gate offset size was evaluated by utilizing a cold cathode electron beam. Various beam sizes were employed to achieve a small FSS, and subsequently, the smallest beam was utilized to examine the impact of gate offset size. In doing so, the smallest FSS of 0.25 mm vertical and 0.33 mm horizontal was attained without the utilization of any additional focusing lens. This illustrates that by adjusting the beam size and gate offset size, it is possible to attain a small FSS, facilitating the development of an economically viable x-ray imaging beam.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140754071","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}
We have investigated the behavior of current flow across an inhomogeneous Schottky diode (SD) as a function of temperature by numerical simulation. We have used the modified thermionic emission (TE) current expression with a Gaussian distribution of potential barrier heights. This modified TE model assumes the presence of a series of low-barrier patches at the Schottky contact and semiconductor interface. First, we have discussed the behavior of the patch current compound relative to the TE compound in the inhomogeneous SD at 300, 200, and 100 K, as a function of standard deviation and the number of circular patches N. Then, we have investigated the behavior of temperature- and bias-dependent and bias-independent current vs voltage (I–V–T) characteristics in the 75–300 K range. In bias-dependent I–V–T curves obtained for σ1=4.35×10−5cm2/3V1/3 and σ2=7.35×10−5cm2/3V1/3 at N1=1.81×106 or N2=1.81×108, an intersection behavior has been observed in the I–V curve at 75 K for σ2 at both N values; however, the same behavior has been not observed for σ1 at both N values due to σ1<σ2. That is, the current for σ2 at 75 K has exceeded the current at higher temperatures. This behavior has been ascribed to the effective BH to decrease with decreasing temperature value. In the I–V–T curves independent of bias, such an intersection has not been observed for σ1 while it has been observed for σ2 in the I–V curves at both 75 and 100 K. Thus, it has been concluded that the bias-dependeσnt I–V equations must be used to avoid this intersection behavior while fitting the experimental I–V curve of an SD to the theoretical I–V curve.
我们通过数值模拟研究了不均匀肖特基二极管（SD）上的电流随温度变化的行为。我们使用了修正的热释电 (TE) 电流表达式，其势垒高度呈高斯分布。这种改进的热释电模型假定在肖特基接触和半导体界面上存在一系列低势垒贴片。首先，我们讨论了在 300、200 和 100 K 的不均匀 SD 中，贴片电流化合物相对于 TE 化合物的行为，这是标准偏差和圆形贴片数量 N 的函数。在 N1=1.81×106 或 N2=1.81×108 时，σ1=4.35×10-5cm2/3V1/3 和 σ2=7.35×10-5cm2/3V1/3 的 I-V-T 曲线中，两种 N 值下的 σ2 在 75 K 的 I-V 曲线中都观察到了交集行为；然而，由于 σ1<σ2 的原因，两种 N 值下的σ1 都没有观察到相同的行为。也就是说，σ2 在 75 K 时的电流超过了更高温度下的电流。这种行为是由于有效 BH 随温度值的降低而减小。在与偏压无关的 I-V-T 曲线中，σ1 没有观察到这种相交现象，而在 75 K 和 100 K 的 I-V 曲线中，σ2 却观察到了这种相交现象。因此，得出的结论是，在将 SD 的实验 I-V 曲线拟合到理论 I-V 曲线时，必须使用与偏压相关的 I-V 方程来避免这种相交行为。
{"title":"Analysis of temperature-dependent current–voltage characteristics of Schottky diodes by the modified thermionic emission current model","authors":"A. Turut","doi":"10.1116/6.0003463","DOIUrl":"https://doi.org/10.1116/6.0003463","url":null,"abstract":"We have investigated the behavior of current flow across an inhomogeneous Schottky diode (SD) as a function of temperature by numerical simulation. We have used the modified thermionic emission (TE) current expression with a Gaussian distribution of potential barrier heights. This modified TE model assumes the presence of a series of low-barrier patches at the Schottky contact and semiconductor interface. First, we have discussed the behavior of the patch current compound relative to the TE compound in the inhomogeneous SD at 300, 200, and 100 K, as a function of standard deviation and the number of circular patches N. Then, we have investigated the behavior of temperature- and bias-dependent and bias-independent current vs voltage (I–V–T) characteristics in the 75–300 K range. In bias-dependent I–V–T curves obtained for σ1=4.35×10−5cm2/3V1/3 and σ2=7.35×10−5cm2/3V1/3 at N1=1.81×106 or N2=1.81×108, an intersection behavior has been observed in the I–V curve at 75 K for σ2 at both N values; however, the same behavior has been not observed for σ1 at both N values due to σ1<σ2. That is, the current for σ2 at 75 K has exceeded the current at higher temperatures. This behavior has been ascribed to the effective BH to decrease with decreasing temperature value. In the I–V–T curves independent of bias, such an intersection has not been observed for σ1 while it has been observed for σ2 in the I–V curves at both 75 and 100 K. Thus, it has been concluded that the bias-dependeσnt I–V equations must be used to avoid this intersection behavior while fitting the experimental I–V curve of an SD to the theoretical I–V curve.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"141 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140369077","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 rising levels of water pollution and climate change contribute to water shortages. These factors influence the loss of the environment’s biodiversity and threaten human health. Toxic dye pigments from industries are a significant source of pollution. In this article, we present the synthesis method, characteristics, and photocatalytic properties of the CuO-ZnO nanocomposite, which may affect the degree of decomposition of dyes found in water. The nanocomposite consisting of copper oxide nanowires with zinc oxide nanostructures (CuO-ZnO nanocomposite) was prepared by physical vapor deposition and thermal oxidation methods. The crystalline structure, surface topographies and morphologies, elemental composition, and optical properties of the obtained samples were studied with various techniques such as x-ray diffraction analysis, high-resolution transmission electron microscopy, field emission scanning electron microscopy, energy dispersive x-ray analysis, and UV-vis spectroscopy. The photocatalytic activity of the nanocomposite was measured by testing the degradation of methylene blue under visible irradiation. An increase in the photocatalytic activity of the nanocomposite was observed compared to pure CuO and ZnO. The CuO-ZnO nanocomposite demonstrated a high dye degradation of about 94% during 120 min.
日益严重的水污染和气候变化导致水资源短缺。这些因素影响着环境生物多样性的丧失，并威胁着人类健康。来自工业的有毒染料颜料是一个重要的污染源。本文介绍了可能影响水中染料分解程度的 CuO-ZnO 纳米复合材料的合成方法、特性和光催化性能。利用物理气相沉积和热氧化方法制备了由氧化铜纳米线和氧化锌纳米结构组成的纳米复合材料（CuO-ZnO 纳米复合材料）。利用 X 射线衍射分析、高分辨率透射电子显微镜、场发射扫描电子显微镜、能量色散 X 射线分析和紫外可见光谱等多种技术研究了所得样品的晶体结构、表面形貌、元素组成和光学性质。通过测试亚甲基蓝在可见光照射下的降解情况，测量了纳米复合材料的光催化活性。与纯 CuO 和 ZnO 相比，纳米复合材料的光催化活性有所提高。在 120 分钟内，CuO-ZnO 纳米复合材料的染料降解率高达 94%。
{"title":"CuO-ZnO nanocomposite for photocatalytic application","authors":"Joanna Rymarczyk, I. Stępińska","doi":"10.1116/6.0003482","DOIUrl":"https://doi.org/10.1116/6.0003482","url":null,"abstract":"The rising levels of water pollution and climate change contribute to water shortages. These factors influence the loss of the environment’s biodiversity and threaten human health. Toxic dye pigments from industries are a significant source of pollution. In this article, we present the synthesis method, characteristics, and photocatalytic properties of the CuO-ZnO nanocomposite, which may affect the degree of decomposition of dyes found in water. The nanocomposite consisting of copper oxide nanowires with zinc oxide nanostructures (CuO-ZnO nanocomposite) was prepared by physical vapor deposition and thermal oxidation methods. The crystalline structure, surface topographies and morphologies, elemental composition, and optical properties of the obtained samples were studied with various techniques such as x-ray diffraction analysis, high-resolution transmission electron microscopy, field emission scanning electron microscopy, energy dispersive x-ray analysis, and UV-vis spectroscopy. The photocatalytic activity of the nanocomposite was measured by testing the degradation of methylene blue under visible irradiation. An increase in the photocatalytic activity of the nanocomposite was observed compared to pure CuO and ZnO. The CuO-ZnO nanocomposite demonstrated a high dye degradation of about 94% during 120 min.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"41 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140376783","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}
Jiechao Jiang, Nonso Chetuya, E. Meletis, Joseph H. Ngai, Gordon J. Grzybowski, Bruce Claflin
Two distinct ultra-thin Ge1−xSnx (x ≤ 0.1) epilayers were deposited on (001) Si substrates at 457 and 313 °C through remote plasma-enhanced chemical vapor deposition. These films are considered potential initiation layers for synthesizing thick epitaxial GeSn films. The GeSn film deposited at 313 °C has a thickness of 10 nm and exhibits a highly epitaxial continuous structure with its lattice being compressed along the interface plane to coherently match Si without mismatch dislocations. The GeSn film deposited at 457 °C exhibits a discrete epitaxial island-like morphology with a peak height of ∼30 nm and full-width half maximum (FWHM) varying from 20 to 100 nm. GeSn islands with an FWHM smaller than 20 nm are defect free, whereas those exceeding 25 nm encompass nanotwins and/or stacking faults. The GeSn islands form two-dimensional modulated superlattice structures at the interface with Si. The GeSn film deposited at 457 °C possesses a lower Sn content compared to the one deposited at lower temperature. The potential impact of using these two distinct ultra-thin layers as initiation layers for the direct growth of thicker GeSn epitaxial films on (001) Si substrates is discussed.
{"title":"Temperature-dependent morphology and composition of ultra-thin GeSn epilayers prepared by remote plasma enhanced chemical vapor deposition","authors":"Jiechao Jiang, Nonso Chetuya, E. Meletis, Joseph H. Ngai, Gordon J. Grzybowski, Bruce Claflin","doi":"10.1116/6.0003445","DOIUrl":"https://doi.org/10.1116/6.0003445","url":null,"abstract":"Two distinct ultra-thin Ge1−xSnx (x ≤ 0.1) epilayers were deposited on (001) Si substrates at 457 and 313 °C through remote plasma-enhanced chemical vapor deposition. These films are considered potential initiation layers for synthesizing thick epitaxial GeSn films. The GeSn film deposited at 313 °C has a thickness of 10 nm and exhibits a highly epitaxial continuous structure with its lattice being compressed along the interface plane to coherently match Si without mismatch dislocations. The GeSn film deposited at 457 °C exhibits a discrete epitaxial island-like morphology with a peak height of ∼30 nm and full-width half maximum (FWHM) varying from 20 to 100 nm. GeSn islands with an FWHM smaller than 20 nm are defect free, whereas those exceeding 25 nm encompass nanotwins and/or stacking faults. The GeSn islands form two-dimensional modulated superlattice structures at the interface with Si. The GeSn film deposited at 457 °C possesses a lower Sn content compared to the one deposited at lower temperature. The potential impact of using these two distinct ultra-thin layers as initiation layers for the direct growth of thicker GeSn epitaxial films on (001) Si substrates is discussed.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"46 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140373482","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}
Carlos Rodriguez, Jairo Viola, Yangquan Chen, Joaquín Álvarez
The plasma process plays a pivotal role in the semiconductor industry, facilitating the creation of transistors and memory storage cells. This fourth state of matter is achieved by energizing a gas with radio-frequency electrical power, initiating and maintaining a stable plasma during the process cycles. Given that plasma behaves as an impedance component, an impedance-matching network becomes essential for optimizing power transfer from the source to the load (plasma). While various control strategies have been proposed for different network configurations, such as L, T, and Π networks, our work focuses on the L-type network due to its simplicity and extensive application in this domain. Several significant challenges have been identified in the existing literature, including slow dynamics, a non-monotonic decline in the reflected power, and substantial deviation in the capacitors’ path. These issues collectively impact the overall performance of the matching control system. In this article, we present a new methodology to obtain a nonlinear state-space model of the matching network for its analysis and design a proportional-integral combined with feedforward control and a control Lyapunov-barrier function to assess their effectiveness in achieving convergence to the desired matching value and guiding the path of the capacitors. These approaches aim to mitigate the recurring issues caused by capacitors moving in the wrong direction, thus improving the stability and efficiency of the impedance-matching process over time.
等离子体工艺在半导体工业中发挥着举足轻重的作用，有助于晶体管和存储单元的制造。这种第四种物质状态是通过用射频电能给气体通电来实现的，在工艺循环过程中启动并保持稳定的等离子体。鉴于等离子体是一种阻抗元件，阻抗匹配网络对于优化从源到负载（等离子体）的功率传输至关重要。虽然针对不同的网络配置（如 L、T 和 Π 网络）提出了各种控制策略，但我们的工作重点是 L 型网络，因为它简单易用，而且在该领域应用广泛。在现有文献中发现了一些重大挑战，包括缓慢的动态、反射功率的非单调下降以及电容器路径的巨大偏差。这些问题共同影响了匹配控制系统的整体性能。在本文中，我们提出了一种新方法来获取匹配网络的非线性状态空间模型进行分析，并设计了一种比例积分结合前馈控制和控制 Lyapunov 屏障函数，以评估它们在实现收敛到所需匹配值和引导电容器路径方面的有效性。这些方法旨在缓解电容器移动方向错误造成的反复问题，从而提高阻抗匹配过程的长期稳定性和效率。
{"title":"Modeling and control of L-type network impedance matching for semiconductor plasma etch","authors":"Carlos Rodriguez, Jairo Viola, Yangquan Chen, Joaquín Álvarez","doi":"10.1116/6.0003444","DOIUrl":"https://doi.org/10.1116/6.0003444","url":null,"abstract":"The plasma process plays a pivotal role in the semiconductor industry, facilitating the creation of transistors and memory storage cells. This fourth state of matter is achieved by energizing a gas with radio-frequency electrical power, initiating and maintaining a stable plasma during the process cycles. Given that plasma behaves as an impedance component, an impedance-matching network becomes essential for optimizing power transfer from the source to the load (plasma). While various control strategies have been proposed for different network configurations, such as L, T, and Π networks, our work focuses on the L-type network due to its simplicity and extensive application in this domain. Several significant challenges have been identified in the existing literature, including slow dynamics, a non-monotonic decline in the reflected power, and substantial deviation in the capacitors’ path. These issues collectively impact the overall performance of the matching control system. In this article, we present a new methodology to obtain a nonlinear state-space model of the matching network for its analysis and design a proportional-integral combined with feedforward control and a control Lyapunov-barrier function to assess their effectiveness in achieving convergence to the desired matching value and guiding the path of the capacitors. These approaches aim to mitigate the recurring issues caused by capacitors moving in the wrong direction, thus improving the stability and efficiency of the impedance-matching process over time.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"59 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140271646","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}
P. Vincent, Federico Panciera, I. Florea, A. Ayari, S. Perisanu, C. S. Cojocaru, Haifa Taoum, Chen Wei, K. Saidov, U. Mirsaidov, Ilias Aguili, Nicholas Blanchard, P. Legagneux, S. Purcell
Optimizing the synthesis of carbon nanotubes (CNTs) for applications like field emission (FE) sources requires a fundamental understanding of the growth kinetics of individual CNTs. In this article, we explore how applying electric fields during CNT synthesis influences the as-grown nanotubes and their FE performance. We observe growth and undertake FE measurements in real time using an environmental transmission electron microscope. This is achieved through a polarizable capacitor gap within a microchip sample heater specifically designed for this purpose. Individual nanotubes are easily resolved and are predominantly single-wall CNTs. At low-applied fields, the growing nanotubes can span the gap and link with the opposite electrode, albeit with some loss due to mechanical failure. With a high-applied field and positive bias for FE, we continue to observe the oriented growth of nanotubes. However, this growth is constrained within the gap due to the possibility of FE occurring during the growth process, which can result in either saturation or damage. At any given time, we have the flexibility to halt the growth process and conduct in situ FE experiments. This approach enables us to comprehensively track the complete development of the CNTs and gain insights into the various mechanisms responsible for limiting the performance of CNT cathodes. Interestingly, we report an original self-oscillation induced destruction mechanism that has not been reported before.
要优化碳纳米管 (CNT) 的合成，使其用于场发射 (FE) 源等应用，就必须从根本上了解单个 CNT 的生长动力学。在本文中，我们将探讨在 CNT 合成过程中施加电场如何影响生长后的纳米管及其 FE 性能。我们使用环境透射电子显微镜实时观察生长情况并进行 FE 测量。这是通过专门为此设计的微芯片样品加热器内的可极化电容器间隙实现的。单个纳米管很容易分辨，而且主要是单壁 CNT。在低电场下，生长中的纳米管可以跨越间隙并与对面的电极连接，尽管会因机械故障而造成一些损失。在高施加磁场和正偏置 FE 的情况下，我们继续观察到纳米管的定向生长。然而，由于在生长过程中可能发生 FE，从而导致饱和或损坏，因此这种生长在间隙内受到限制。在任何时候，我们都可以灵活地停止生长过程，并进行原位 FE 实验。这种方法使我们能够全面跟踪碳纳米管的整个发展过程，并深入了解限制碳纳米管阴极性能的各种机制。有趣的是，我们报告了一种前所未有的自振荡诱导破坏机制。
{"title":"Field emission characterization of field-aligned carbon nanotubes synthesized in an environmental transmission electron microscope","authors":"P. Vincent, Federico Panciera, I. Florea, A. Ayari, S. Perisanu, C. S. Cojocaru, Haifa Taoum, Chen Wei, K. Saidov, U. Mirsaidov, Ilias Aguili, Nicholas Blanchard, P. Legagneux, S. Purcell","doi":"10.1116/6.0003413","DOIUrl":"https://doi.org/10.1116/6.0003413","url":null,"abstract":"Optimizing the synthesis of carbon nanotubes (CNTs) for applications like field emission (FE) sources requires a fundamental understanding of the growth kinetics of individual CNTs. In this article, we explore how applying electric fields during CNT synthesis influences the as-grown nanotubes and their FE performance. We observe growth and undertake FE measurements in real time using an environmental transmission electron microscope. This is achieved through a polarizable capacitor gap within a microchip sample heater specifically designed for this purpose. Individual nanotubes are easily resolved and are predominantly single-wall CNTs. At low-applied fields, the growing nanotubes can span the gap and link with the opposite electrode, albeit with some loss due to mechanical failure. With a high-applied field and positive bias for FE, we continue to observe the oriented growth of nanotubes. However, this growth is constrained within the gap due to the possibility of FE occurring during the growth process, which can result in either saturation or damage. At any given time, we have the flexibility to halt the growth process and conduct in situ FE experiments. This approach enables us to comprehensively track the complete development of the CNTs and gain insights into the various mechanisms responsible for limiting the performance of CNT cathodes. Interestingly, we report an original self-oscillation induced destruction mechanism that has not been reported before.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"76 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140273952","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}
Ryo Miyazawa, Haruto Suzuki, Hibiki Takeda, M. Miura, B. Ahmmad, Fumihiko Hirose
Sodium adsorption on nanometer-thick-TiO2-channel thin-film transistors (TFTs) are examined for enhancing the drain current. In the TFTs, the channel thickness of TiO2 is set as thin as ∼16 nm. The TiO2 film is deposited by atomic layer deposition using plasma excited humified Ar, followed by crystallization into the anatase phase by thermal annealing at 500 °C in air. The gate oxide is a 300 nm thick SiO2 film, which is grown on a highly doped n+ Si substrate. The n+ Si substrate is used as the gate electrode. The drain and source electrodes of Ti are deposited by an electron beam evaporation at room temperature. The TiO2 channel is covered with multiple layers of aluminum silicate and SiO2 films to enhance the Na sorptivity. The multiple films consist of combinations of 1 nm thick SiO2 and 0.16 nm thick aluminum silicate. The channel length and width are 60 and 1000 μm, respectively. The TFT without the Na adsorption exhibits a field effect mobility of ∼0.5 cm2/V s, where the drain current is recorded around 30 μA with a gate voltage of 10 V. With immersion of the TFT in a 10 mM NaCl solution, the drain current is enhanced to the order of mA. The simulation with an equivalent circuit with source and drain resistances suggests that the field effect mobility is enhanced to ∼30 cm2/V s with the adsorption of Na. In this paper, we discuss the operation mechanism of the Na adsorbed TiO2 TFT and its applicability as TFT-based high current switch devices and sensors.
研究了钠在纳米厚二氧化钛沟道薄膜晶体管（TFT）上的吸附作用，以提高漏极电流。在 TFT 中，TiO2 沟道的厚度设定为 16 纳米。TiO2 薄膜是通过使用等离子体激发的腐化氩气进行原子层沉积，然后在空气中以 500 °C 的温度热退火结晶成锐钛相。栅极氧化物是在高掺杂 n+ 硅衬底上生长的 300 nm 厚的 SiO2 薄膜。n+ 硅衬底用作栅极。漏极和源极的钛是在室温下通过电子束蒸发沉积的。TiO2 沟道上覆盖了多层硅酸铝和 SiO2 薄膜，以提高 Na 吸水率。多层薄膜由 1 纳米厚的二氧化硅和 0.16 纳米厚的硅酸铝组合而成。沟道长度和宽度分别为 60 微米和 1000 微米。未吸附 Na 的 TFT 的场效应迁移率为 0.5 cm2/V s，在栅极电压为 10 V 时，漏极电流约为 30 μA。将 TFT 浸入 10 mM NaCl 溶液后，漏极电流增强到 mA 量级。利用具有源极和漏极电阻的等效电路进行的模拟表明，在吸附 Na 后，场效应迁移率提高到 30 cm2/V s。本文讨论了 Na 吸附 TiO2 TFT 的运行机制及其作为基于 TFT 的大电流开关器件和传感器的适用性。
{"title":"Sodium adsorption on nanometer-thick TiO2 channel thin-film transistors for enhanced drain currents","authors":"Ryo Miyazawa, Haruto Suzuki, Hibiki Takeda, M. Miura, B. Ahmmad, Fumihiko Hirose","doi":"10.1116/6.0003217","DOIUrl":"https://doi.org/10.1116/6.0003217","url":null,"abstract":"Sodium adsorption on nanometer-thick-TiO2-channel thin-film transistors (TFTs) are examined for enhancing the drain current. In the TFTs, the channel thickness of TiO2 is set as thin as ∼16 nm. The TiO2 film is deposited by atomic layer deposition using plasma excited humified Ar, followed by crystallization into the anatase phase by thermal annealing at 500 °C in air. The gate oxide is a 300 nm thick SiO2 film, which is grown on a highly doped n+ Si substrate. The n+ Si substrate is used as the gate electrode. The drain and source electrodes of Ti are deposited by an electron beam evaporation at room temperature. The TiO2 channel is covered with multiple layers of aluminum silicate and SiO2 films to enhance the Na sorptivity. The multiple films consist of combinations of 1 nm thick SiO2 and 0.16 nm thick aluminum silicate. The channel length and width are 60 and 1000 μm, respectively. The TFT without the Na adsorption exhibits a field effect mobility of ∼0.5 cm2/V s, where the drain current is recorded around 30 μA with a gate voltage of 10 V. With immersion of the TFT in a 10 mM NaCl solution, the drain current is enhanced to the order of mA. The simulation with an equivalent circuit with source and drain resistances suggests that the field effect mobility is enhanced to ∼30 cm2/V s with the adsorption of Na. In this paper, we discuss the operation mechanism of the Na adsorbed TiO2 TFT and its applicability as TFT-based high current switch devices and sensors.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140269705","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}
Siddiqa Ismail, W. Ahmed, Muhammad Farooq, N. U. Rehman
The plasma-liquid interaction (PLI) technique has been employed as a green approach for the synthesis of gold-silver core-shell nanoparticles (Au@AgNPs) using a two-step method. In the first step, the Au seed particles were grown by the PLI technique. Subsequently, the formation of Ag shell was achieved by adding AgNO3 to the solution containing Au seeds and placing it under the atmospheric pressure plasma. The growth of Ag shell on Au seeds was optimized and secondary nucleation was avoided by tuning the discharge current, precursor concentration, and stabilizer (d-fructose) concentration. The shell thickness of Ag was also changed by changing the concentration of AgNO3 in the solution. UV-Vis spectroscopy, scanning electron microscopy, and energy-dispersive x-ray spectroscopy were used to analyze the synthesized nanoparticles. Furthermore, the particles were employed for catalysis and surface enhanced Raman spectroscopy (SERS)-based molecular trace detection. The catalytic efficiency of the NPs was investigated for the reduction of four molecules, i.e., 4-nitrophenol, methyl orange, Congo red, and rhodamine B. The SERS-based trace detection was studied for rhodamine 6G using the substrates of synthesized NPs. In both cases, core-shell nanoparticles showed far superior performance compared to the seed Au nanoparticles.
等离子体-液体相互作用（PLI）技术作为一种绿色方法，采用两步法合成了金银核壳纳米粒子（Au@AgNPs）。第一步，利用 PLI 技术生长金种子颗粒。随后，在含有金种子的溶液中加入 AgNO3，并将其置于常压等离子体下，从而形成银壳。通过调整放电电流、前驱体浓度和稳定剂（d-果糖）浓度，优化了金种子上银壳的生长并避免了二次成核。此外，还通过改变溶液中 AgNO3 的浓度来改变银壳的厚度。紫外可见光谱、扫描电子显微镜和能量色散 X 射线光谱被用来分析合成的纳米粒子。此外，这些颗粒还被用于催化和基于表面增强拉曼光谱（SERS）的分子痕量检测。研究了纳米粒子对 4-硝基苯酚、甲基橙、刚果红和罗丹明 B 四种分子还原的催化效率。在这两种情况下，核壳纳米粒子的性能都远远优于种子金纳米粒子。
{"title":"Plasma-assisted synthesis of gold-silver core-shell nanoparticles and their enhanced catalytic dye degradation and surface enhanced Raman spectroscopy performance","authors":"Siddiqa Ismail, W. Ahmed, Muhammad Farooq, N. U. Rehman","doi":"10.1116/6.0003245","DOIUrl":"https://doi.org/10.1116/6.0003245","url":null,"abstract":"The plasma-liquid interaction (PLI) technique has been employed as a green approach for the synthesis of gold-silver core-shell nanoparticles (Au@AgNPs) using a two-step method. In the first step, the Au seed particles were grown by the PLI technique. Subsequently, the formation of Ag shell was achieved by adding AgNO3 to the solution containing Au seeds and placing it under the atmospheric pressure plasma. The growth of Ag shell on Au seeds was optimized and secondary nucleation was avoided by tuning the discharge current, precursor concentration, and stabilizer (d-fructose) concentration. The shell thickness of Ag was also changed by changing the concentration of AgNO3 in the solution. UV-Vis spectroscopy, scanning electron microscopy, and energy-dispersive x-ray spectroscopy were used to analyze the synthesized nanoparticles. Furthermore, the particles were employed for catalysis and surface enhanced Raman spectroscopy (SERS)-based molecular trace detection. The catalytic efficiency of the NPs was investigated for the reduction of four molecules, i.e., 4-nitrophenol, methyl orange, Congo red, and rhodamine B. The SERS-based trace detection was studied for rhodamine 6G using the substrates of synthesized NPs. In both cases, core-shell nanoparticles showed far superior performance compared to the seed Au nanoparticles.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"30 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140276995","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：