M. Krysztof, Paweł Miera, Paweł Urbański, T. Grzebyk, M. Hausladen, Rupert Schreiner
The article presents the process of developing a silicon electron source designed for high-vacuum microelectromechanical system (HV MEMS) devices, i.e., MEMS electron microscope and MEMS x-ray source. Technological constraints and issues of such an electron source are explained. The transition from emitters made of carbon nanotubes to emitters made of pure silicon is described. Overall, the final electron source consists of a silicon tip emitter and a silicon gate electrode integrated on the same glass substrate. The source generates an electron beam without any carbon nanotube coverage. It generates a high and stable electron current and works after the final bonding process of an HV MEMS device.
文章介绍了为高真空微机电系统（HV MEMS）设备（即 MEMS 电子显微镜和 MEMS X 射线源）设计的硅电子源的开发过程。本文解释了这种电子源的技术限制和问题。介绍了从碳纳米管发射器到纯硅发射器的转变过程。总之，最终的电子源由集成在同一玻璃基板上的硅尖发射器和硅栅电极组成。该电子源产生的电子束不覆盖任何碳纳米管。它能产生较高且稳定的电子电流，并能在高压微机电系统设备的最终接合过程后工作。
{"title":"Integrated silicon electron source for high vacuum microelectromechanical system devices","authors":"M. Krysztof, Paweł Miera, Paweł Urbański, T. Grzebyk, M. Hausladen, Rupert Schreiner","doi":"10.1116/6.0003385","DOIUrl":"https://doi.org/10.1116/6.0003385","url":null,"abstract":"The article presents the process of developing a silicon electron source designed for high-vacuum microelectromechanical system (HV MEMS) devices, i.e., MEMS electron microscope and MEMS x-ray source. Technological constraints and issues of such an electron source are explained. The transition from emitters made of carbon nanotubes to emitters made of pure silicon is described. Overall, the final electron source consists of a silicon tip emitter and a silicon gate electrode integrated on the same glass substrate. The source generates an electron beam without any carbon nanotube coverage. It generates a high and stable electron current and works after the final bonding process of an HV MEMS device.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"122 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140088146","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}
Abhijit Das, N. K. Singh, Laishram Robindro Singh, M. Sarkar
An Aluminum Oxide (Al2O3) nanorod (NR) array–based device has been synthesized upon an Al2O3 thin film (TF) by electron beam (E-beam) evaporation with a glancing angle deposition technique. The complete fabrication has been done inside a vacuum coating unit. The Al2O3 nanostructures have been fabricated on a silicon substrate. Field emission scanning electron microscopy and transmission electron microscopy show a vertically aligned Al2O3 NR array. From the Tauc plot, the optical band energies are estimated as 5 eV and 5.5 eV for the bare Al2O3 TF and Al2O3 NR/Al2O3 TF devices, respectively. Significant improvement has been observed in photosensitivity by 10 fold, detectivity by 4.2 fold, and noise equivalent power (NEP) by 16.5 fold for the Al2O3 NR/Al2O3 TF device compared with the Al2O3 TF. The Al2O3 NR/Al2O3 TF device exhibits a very fast photoswitching response (rise time = 0.15 s and fall time = 0.13 s). Therefore, the Al2O3 NR/Al2O3 TF device proves to be a prominent candidate for next-generation optoelectronic device applications.
{"title":"Improved optical and electrical response by glancing angle synthesized Al2O3 nanorod array device","authors":"Abhijit Das, N. K. Singh, Laishram Robindro Singh, M. Sarkar","doi":"10.1116/6.0003416","DOIUrl":"https://doi.org/10.1116/6.0003416","url":null,"abstract":"An Aluminum Oxide (Al2O3) nanorod (NR) array–based device has been synthesized upon an Al2O3 thin film (TF) by electron beam (E-beam) evaporation with a glancing angle deposition technique. The complete fabrication has been done inside a vacuum coating unit. The Al2O3 nanostructures have been fabricated on a silicon substrate. Field emission scanning electron microscopy and transmission electron microscopy show a vertically aligned Al2O3 NR array. From the Tauc plot, the optical band energies are estimated as 5 eV and 5.5 eV for the bare Al2O3 TF and Al2O3 NR/Al2O3 TF devices, respectively. Significant improvement has been observed in photosensitivity by 10 fold, detectivity by 4.2 fold, and noise equivalent power (NEP) by 16.5 fold for the Al2O3 NR/Al2O3 TF device compared with the Al2O3 TF. The Al2O3 NR/Al2O3 TF device exhibits a very fast photoswitching response (rise time = 0.15 s and fall time = 0.13 s). Therefore, the Al2O3 NR/Al2O3 TF device proves to be a prominent candidate for next-generation optoelectronic device applications.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"148 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140275939","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}
A novel simulation code for the calculation of the time-dependent evolution of helium density profiles in tubular-shaped beam vacuum systems of particle accelerators is presented. The code called TransVac was written in the statistics programming language R using the noncommercial development software RStudio and is based on an analytical approach. In contrast to earlier simulation tools based on analytical computational methods, the new code does not only master the profile calculation in conventional vacuum systems operated at room temperature, but also in fully cryogenic and in nonisothermal systems composed of cryogenic and warm sections. Data of helium adsorption isotherms are used to calculate gas densities profiles in cold vacuum systems with the cryosorption-based wall-pumping effect. The article discusses how the simulation code works and which mathematical algorithm is used. Comparisons between experimental and theoretical data confirm that the software developed provides sufficiently reliable predictions on the propagation behavior of leak-triggered helium pressure waves in cryogenic and room-temperature vacuum systems as well.
本文介绍了一种新型模拟代码，用于计算粒子加速器管形束流真空系统中氦密度剖面随时间变化的情况。该代码名为 TransVac，是使用非商业开发软件 RStudio 以统计编程语言 R 编写的，基于分析方法。与早期基于分析计算方法的模拟工具不同的是，新代码不仅掌握了在室温下运行的传统真空系统中的剖面计算，还掌握了在全低温和由低温段和暖段组成的非等温系统中的剖面计算。氦吸附等温线数据用于计算具有基于低温吸附的壁泵效应的低温真空系统中的气体密度曲线。文章讨论了模拟代码的工作原理和使用的数学算法。实验数据和理论数据之间的比较证实，所开发的软件能够充分可靠地预测低温和室温真空系统中泄漏触发的氦气压力波的传播行为。
{"title":"Simulation of the time-dependent propagation of leak-triggered helium density gradients in cryogenic and nonisothermal accelerator vacuum systems","authors":"Stefan Wilfert, F. Chill","doi":"10.1116/6.0003330","DOIUrl":"https://doi.org/10.1116/6.0003330","url":null,"abstract":"A novel simulation code for the calculation of the time-dependent evolution of helium density profiles in tubular-shaped beam vacuum systems of particle accelerators is presented. The code called TransVac was written in the statistics programming language R using the noncommercial development software RStudio and is based on an analytical approach. In contrast to earlier simulation tools based on analytical computational methods, the new code does not only master the profile calculation in conventional vacuum systems operated at room temperature, but also in fully cryogenic and in nonisothermal systems composed of cryogenic and warm sections. Data of helium adsorption isotherms are used to calculate gas densities profiles in cold vacuum systems with the cryosorption-based wall-pumping effect. The article discusses how the simulation code works and which mathematical algorithm is used. Comparisons between experimental and theoretical data confirm that the software developed provides sufficiently reliable predictions on the propagation behavior of leak-triggered helium pressure waves in cryogenic and room-temperature vacuum systems as well.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140282694","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 construction of a low power silicon evaporation source for thin film deposition applications is proposed in this article. A few differently shaped tungsten filaments were mounted inside a quartz glass crucible, which assured an effective heating of silicon wafer pieces. The sublimation process was monitored at filament powers in the range of 8–22 W, which corresponds to temperatures far below the melting point of Si. The operation of the evaporation source requires only the use of a low voltage power supply. All considered models of evaporation sources are characterized by an easy construction. The measurements carried out with the use of a quartz crystal microbalance sensor enabled to determine the deposition rate at different filament powers for all constructed Si sources and confirm the long-term stability of the silicon flux. The experimental data exhibit the Polany–Wigner dependence of the deposition rate as a function of inverse of power at higher filament powers. Auger electron spectroscopy was used to monitor the deposition of Si on Ag(100) under constant silicon flux. The Auger signal recorded from Si and Ag reflects the growth of subsequent silicon layers. This enabled the determination of the Frank–van der Merwe growth mode of Si on Ag(100) at early stages of growth, the formation time of one Si monolayer, and, thus, the deposition rate. The presented designs of the Si source exhibit long time stable evaporation fully controlled by the applied filament power, which is crucial in the precise adsorption of ultrathin Si layers.
本文提出了一种用于薄膜沉积应用的低功率硅蒸发源的构造。在石英玻璃坩埚内安装了一些不同形状的钨丝，以确保硅片的有效加热。在钨丝功率为 8-22 W 的范围内对升华过程进行了监测，其温度远低于硅的熔点。蒸发源的运行只需要使用低压电源。所有型号的蒸发源都具有结构简单的特点。通过使用石英晶体微天平传感器进行测量，可以确定所有构建的硅源在不同灯丝功率下的沉积率，并确认硅流量的长期稳定性。实验数据显示，在灯丝功率较高时，沉积率与功率的倒数呈 Polany-Wigner 依赖关系。在硅通量恒定的情况下，使用欧杰电子能谱监测硅在 Ag（100）上的沉积。从硅和银记录到的欧杰信号反映了后续硅层的生长情况。这样就能确定硅在 Ag(100) 上生长初期的 Frank-van der Merwe 生长模式、一个硅单层的形成时间，从而确定沉积速率。所介绍的硅源设计表现出长时间稳定的蒸发，完全受应用灯丝功率的控制，这对超薄硅层的精确吸附至关重要。
{"title":"Low power silicon evaporation source—Construction, performances, and applications","authors":"S. Kovalchuk, M. Nowicki, I. Morawski","doi":"10.1116/6.0003284","DOIUrl":"https://doi.org/10.1116/6.0003284","url":null,"abstract":"The construction of a low power silicon evaporation source for thin film deposition applications is proposed in this article. A few differently shaped tungsten filaments were mounted inside a quartz glass crucible, which assured an effective heating of silicon wafer pieces. The sublimation process was monitored at filament powers in the range of 8–22 W, which corresponds to temperatures far below the melting point of Si. The operation of the evaporation source requires only the use of a low voltage power supply. All considered models of evaporation sources are characterized by an easy construction. The measurements carried out with the use of a quartz crystal microbalance sensor enabled to determine the deposition rate at different filament powers for all constructed Si sources and confirm the long-term stability of the silicon flux. The experimental data exhibit the Polany–Wigner dependence of the deposition rate as a function of inverse of power at higher filament powers. Auger electron spectroscopy was used to monitor the deposition of Si on Ag(100) under constant silicon flux. The Auger signal recorded from Si and Ag reflects the growth of subsequent silicon layers. This enabled the determination of the Frank–van der Merwe growth mode of Si on Ag(100) at early stages of growth, the formation time of one Si monolayer, and, thus, the deposition rate. The presented designs of the Si source exhibit long time stable evaporation fully controlled by the applied filament power, which is crucial in the precise adsorption of ultrathin Si layers.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"7 20","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140269922","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}
Slanted gratings, commonly used for manipulating light in various applications, are typically fabricated using conventional top-down methods. However, these methods have limitations on material choice. This paper explores the use of glancing angle deposition (GLAD) to fabricate slanted gratings with various materials and slant angles on silicon (Si) and quartz (SiO2) substrates. The process involves the first step of creating a template using electron beam lithography, lift-off, and dry etching, and the second step of electron beam evaporation at a glancing angle on the prefabricated template. The template consists of grating structures with very shallow trenches. Different materials, such as chromium (Cr), copper (Cu), aluminum oxide (Al2O3), and titanium oxide (TiO2), were used in the GLAD process to create slanted grating structures on Si or SiO2 substrates, showcasing their versatility. Here, the formation of the slanted grating is due to the shadowing effect that leads to deposition onto the protruded grating lines but not into the trench. Using TiO2 as the source material, the GLAD technique can produce slanted gratings with various angles by adjusting the deposition angle. The optical characteristics of the slanted grating prepared using GLAD were verified through simulations with COMSOL software, confirming its excellent light guide performance.
{"title":"Fabrication of slanted gratings by using glancing angle deposition","authors":"Hongwen Wu, Aixi Pan, Chenxu Zhu, Bo Cui","doi":"10.1116/6.0003479","DOIUrl":"https://doi.org/10.1116/6.0003479","url":null,"abstract":"Slanted gratings, commonly used for manipulating light in various applications, are typically fabricated using conventional top-down methods. However, these methods have limitations on material choice. This paper explores the use of glancing angle deposition (GLAD) to fabricate slanted gratings with various materials and slant angles on silicon (Si) and quartz (SiO2) substrates. The process involves the first step of creating a template using electron beam lithography, lift-off, and dry etching, and the second step of electron beam evaporation at a glancing angle on the prefabricated template. The template consists of grating structures with very shallow trenches. Different materials, such as chromium (Cr), copper (Cu), aluminum oxide (Al2O3), and titanium oxide (TiO2), were used in the GLAD process to create slanted grating structures on Si or SiO2 substrates, showcasing their versatility. Here, the formation of the slanted grating is due to the shadowing effect that leads to deposition onto the protruded grating lines but not into the trench. Using TiO2 as the source material, the GLAD technique can produce slanted gratings with various angles by adjusting the deposition angle. The optical characteristics of the slanted grating prepared using GLAD were verified through simulations with COMSOL software, confirming its excellent light guide performance.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"750 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140273219","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. Yasar, Richard E. Muller, A. Khoshakhlagh, S. Keo
This paper presents a time- and cost-effective method for the large-area fabrication of photonic crystals with nanometer-scale features on the GaN material. The proposed technique utilizes e-beam lithography and double hard mask layers to enable the high aspect ratio etching of the nanoscale features. The double hard mask layer, which is a photoresist, platinum (Pt) and SiO2, is very strong against plasma etching, making it an effective barrier layer to protect the underlying material during the etching process. The fabricated photonic crystal exhibits a high aspect ratio and excellent uniformity over a large area. This technique can be used for the time-effective production of photonic crystals for various applications such as optical sensing, spectroscopy, and telecommunications. The method presented in this paper can also be extended to other material systems beyond GaN. The proposed approach provides a promising route to achieve the large-area fabrication of nanometer-scale structures with high aspect ratios using e-beam lithography.
{"title":"Large-area fabrication of nanometer-scale features on GaN using e-beam lithography","authors":"F. Yasar, Richard E. Muller, A. Khoshakhlagh, S. Keo","doi":"10.1116/6.0003270","DOIUrl":"https://doi.org/10.1116/6.0003270","url":null,"abstract":"This paper presents a time- and cost-effective method for the large-area fabrication of photonic crystals with nanometer-scale features on the GaN material. The proposed technique utilizes e-beam lithography and double hard mask layers to enable the high aspect ratio etching of the nanoscale features. The double hard mask layer, which is a photoresist, platinum (Pt) and SiO2, is very strong against plasma etching, making it an effective barrier layer to protect the underlying material during the etching process. The fabricated photonic crystal exhibits a high aspect ratio and excellent uniformity over a large area. This technique can be used for the time-effective production of photonic crystals for various applications such as optical sensing, spectroscopy, and telecommunications. The method presented in this paper can also be extended to other material systems beyond GaN. The proposed approach provides a promising route to achieve the large-area fabrication of nanometer-scale structures with high aspect ratios using e-beam lithography.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"22 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140426626","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 presence of amorphous oxide layers can significantly affect the coherent time of superconducting qubits due to their high dielectric loss. Typically, the surface oxides of superconductor films exhibit lossy and unstable behavior when exposed to air. To increase the coherence time, it is essential for qubits to have stable and low dielectric loss oxides, either as barrier or passivation layers. In this study, we highlight the robust and stable nature of an amorphous tantalum oxide layer formed on α-Ta (110) film by employing chemical and structural analyses. Such kind of oxide layer forms in a self-limiting process on the surface of α-Ta (110) film in piranha solution, yielding stable thickness and steady chemical composition. Quarter-wavelength coplanar waveguide resonators are made to study the loss of this oxide. One resonator has a Qi of 3.0 × 106 in the single photon region. The Qi of most devices are higher than 2.0 × 106. Moreover, most of them are still over 1 × 106 even after exposed to air for months. Based on these findings, we propose an all-tantalum superconducting qubit utilizing such oxide as passivation layers, which possess low dielectric loss and improved stability.
{"title":"Stable and low loss oxide layer on α-Ta (110) film for superconducting qubits","authors":"Zengqian Ding, Boyi Zhou, Tao Wang, Lina Yang, Yanfu Wu, Xiao Cai, Kanglin Xiong, Jiagui Feng","doi":"10.1116/6.0003368","DOIUrl":"https://doi.org/10.1116/6.0003368","url":null,"abstract":"The presence of amorphous oxide layers can significantly affect the coherent time of superconducting qubits due to their high dielectric loss. Typically, the surface oxides of superconductor films exhibit lossy and unstable behavior when exposed to air. To increase the coherence time, it is essential for qubits to have stable and low dielectric loss oxides, either as barrier or passivation layers. In this study, we highlight the robust and stable nature of an amorphous tantalum oxide layer formed on α-Ta (110) film by employing chemical and structural analyses. Such kind of oxide layer forms in a self-limiting process on the surface of α-Ta (110) film in piranha solution, yielding stable thickness and steady chemical composition. Quarter-wavelength coplanar waveguide resonators are made to study the loss of this oxide. One resonator has a Qi of 3.0 × 106 in the single photon region. The Qi of most devices are higher than 2.0 × 106. Moreover, most of them are still over 1 × 106 even after exposed to air for months. Based on these findings, we propose an all-tantalum superconducting qubit utilizing such oxide as passivation layers, which possess low dielectric loss and improved stability.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"30 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140431761","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 study the interaction with photodetectors of near infrared (NIR) laser light with power P in the range of mW and period τ = 3.55 fs (wavelength λ = 1064 nm, frequency ν = 0.28 PHz). We fabricate the photodetectors by depositing different sequences of thin TiO2/TiN nano-laminates onto glass substrates using atomic layer deposition (ALD). To evaluate the photodetector's performance, we assume Pτ to be the energy transferred to them from NIR laser light, allowing us to extract the photodetector's inductance L at zero bias voltage, and to explicitly link P to the photocurrent ΔI, or photovoltage ΔV, generated by the photodetector. Such a link is observed in the literature, but not justified. We further assume Pλ = P λ/lact to be the effective power illuminating the photodetector with size lact. This assumption enables us to determine the photodetector's current responsivity (πI), noise equivalent power (NEP), and detectivity (D). To establish whether Pτ and Pλ correctly account for the energy and the power involved in the photodetector's interaction with light, we compare L, πI, NEP, and D of our photodetectors to the corresponding parameters of state-of-the-art (SOA) devices reported in the literature. The comparison indicates that the L, πI, NEP, and D of our photodetectors are in the range of SOA devices, thus validating our assumptions on Pτ and Pλ. Finally, our findings provide suggestions on how to improve thin ALD TiO2/TiN nano-laminates as suitable active materials in photodetectors.
我们研究了功率 P 在 mW 范围内、周期 τ = 3.55 fs（波长 λ = 1064 nm，频率 ν = 0.28 PHz）的近红外（NIR）激光与光电探测器的相互作用。我们利用原子层沉积（ALD）技术在玻璃基板上沉积不同序列的 TiO2/TiN 纳米薄层，从而制造出光电探测器。为了评估光电探测器的性能，我们假定 Pτ 是近红外激光传递给它们的能量，这样我们就可以提取光电探测器在零偏置电压下的电感 L，并将 P 与光电探测器产生的光电流 ΔI 或光电电压 ΔV 明确联系起来。这种联系在文献中有所提及，但并不充分。我们进一步假设 Pλ = P λ/lact 是照射到光电探测器的有效功率，其大小为 lact。通过这一假设，我们可以确定光电探测器的电流响应度 (πI)、噪声等效功率 (NEP) 和探测度 (D)。为了确定 Pτ 和 Pλ 是否正确反映了光电探测器与光相互作用时所涉及的能量和功率，我们将光电探测器的 L、πI、NEP 和 D 与文献中报道的最先进（SOA）器件的相应参数进行了比较。比较结果表明，我们的光电探测器的 L、πI、NEP 和 D 均在 SOA 器件的范围内，从而验证了我们对 Pτ 和 Pλ 的假设。最后，我们的研究结果为如何改进 ALD TiO2/TiN 纳米薄层作为光电探测器中合适的活性材料提供了建议。
{"title":"Performance evaluation of atomic layer deposited TiO2/TiN nanolaminates used as infrared photodetectors","authors":"G. Scarel, O. Kokhan, V. D. Wheeler","doi":"10.1116/6.0003139","DOIUrl":"https://doi.org/10.1116/6.0003139","url":null,"abstract":"We study the interaction with photodetectors of near infrared (NIR) laser light with power P in the range of mW and period τ = 3.55 fs (wavelength λ = 1064 nm, frequency ν = 0.28 PHz). We fabricate the photodetectors by depositing different sequences of thin TiO2/TiN nano-laminates onto glass substrates using atomic layer deposition (ALD). To evaluate the photodetector's performance, we assume Pτ to be the energy transferred to them from NIR laser light, allowing us to extract the photodetector's inductance L at zero bias voltage, and to explicitly link P to the photocurrent ΔI, or photovoltage ΔV, generated by the photodetector. Such a link is observed in the literature, but not justified. We further assume Pλ = P λ/lact to be the effective power illuminating the photodetector with size lact. This assumption enables us to determine the photodetector's current responsivity (πI), noise equivalent power (NEP), and detectivity (D). To establish whether Pτ and Pλ correctly account for the energy and the power involved in the photodetector's interaction with light, we compare L, πI, NEP, and D of our photodetectors to the corresponding parameters of state-of-the-art (SOA) devices reported in the literature. The comparison indicates that the L, πI, NEP, and D of our photodetectors are in the range of SOA devices, thus validating our assumptions on Pτ and Pλ. Finally, our findings provide suggestions on how to improve thin ALD TiO2/TiN nano-laminates as suitable active materials in photodetectors.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140444876","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. Buchner, M. Hausladen, M. Bartl, M. Bachmann, R. Schreiner
We investigate the influence of the geometry and doping level on the performance of n-type silicon nanowire field emitters on silicon pillar structures. Therefore, multiple cathodes with 50 by 50 pillar arrays (diameter: 5 μm, height: 30 μm, spacing: 50 μm) were fabricated and measured in diode configuration. In the first experiment, we compared two geometry types using the same material. Geometry 1 is black silicon, which is a highly dense surface covering a forest of tightly spaced silicon needles resulting from self-masking during a plasma etching process of single crystal silicon. Geometry 2 are silicon nanowires, which are individual spaced-out nanowires in a crownlike shape resulting from a plasma etching process of single crystal silicon. In the second experiment, we compared two different silicon doping levels [n-type (P), 1–10 and <0.005 Ω cm] for the same geometry. The best performance was achieved with lower doped silicon nanowire samples, emitting 2 mA at an extraction voltage of 1 kV. The geometry/material combination with the best performance was used to assemble an integrated electron source. These electron sources were measured in a triode configuration and reached onset voltages of about 125 V and emission currents of 2.5 mA at extraction voltages of 400 V, while achieving electron transmission rates as high as 85.0%.
我们研究了几何形状和掺杂水平对硅柱结构上 n 型硅纳米线场发射器性能的影响。因此，我们制作了 50 x 50 柱阵列（直径：5 μm，高度：30 μm，间距：50 μm）的多个阴极，并以二极管配置进行了测量。在第一个实验中，我们比较了使用相同材料的两种几何类型。几何形状 1 是黑硅，这是一种高密度表面，覆盖着单晶硅等离子蚀刻过程中自掩膜产生的紧密间隔的硅针森林。几何图形 2 是硅纳米线，这是单晶硅在等离子体蚀刻过程中形成的冠状形状的单个间隔纳米线。在第二个实验中，我们比较了相同几何形状的两种不同硅掺杂水平[n 型 (P)、1-10 和 <0.005 Ω cm]。掺杂程度较低的硅纳米线样品性能最佳，在 1 kV 的提取电压下可发射 2 mA 电流。性能最佳的几何形状/材料组合被用来组装集成电子源。在三极管配置中对这些电子源进行了测量，其起始电压约为 125 V，在 400 V 的萃取电压下发射电流为 2.5 mA，电子传输率高达 85.0%。
{"title":"High current field emission from Si nanowires on pillar structures","authors":"P. Buchner, M. Hausladen, M. Bartl, M. Bachmann, R. Schreiner","doi":"10.1116/6.0003384","DOIUrl":"https://doi.org/10.1116/6.0003384","url":null,"abstract":"We investigate the influence of the geometry and doping level on the performance of n-type silicon nanowire field emitters on silicon pillar structures. Therefore, multiple cathodes with 50 by 50 pillar arrays (diameter: 5 μm, height: 30 μm, spacing: 50 μm) were fabricated and measured in diode configuration. In the first experiment, we compared two geometry types using the same material. Geometry 1 is black silicon, which is a highly dense surface covering a forest of tightly spaced silicon needles resulting from self-masking during a plasma etching process of single crystal silicon. Geometry 2 are silicon nanowires, which are individual spaced-out nanowires in a crownlike shape resulting from a plasma etching process of single crystal silicon. In the second experiment, we compared two different silicon doping levels [n-type (P), 1–10 and <0.005 Ω cm] for the same geometry. The best performance was achieved with lower doped silicon nanowire samples, emitting 2 mA at an extraction voltage of 1 kV. The geometry/material combination with the best performance was used to assemble an integrated electron source. These electron sources were measured in a triode configuration and reached onset voltages of about 125 V and emission currents of 2.5 mA at extraction voltages of 400 V, while achieving electron transmission rates as high as 85.0%.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"19 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140443240","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}
Qingyue Li, Claire Deeb, Hélène Debregeas, J. Pelouard
We report the results of a study on the inductively coupled plasma (ICP) etching of InP at room temperature using Cl2 mixtures (Cl2/N2/H2). The impact of different process parameters, including the RF power, the ICP power, the ion-to-neutral ratio, and the chamber pressure, on the etched profile was investigated. The etch rate, selectivity, and anisotropy of the profile were depicted for each etching recipe. Two types of masks, such as SiO2 and AZ5214 photoresist, were used in this study. The etched InP feature showed a very smooth surface (rms as low as 0.5 nm) and a relatively fast etch rate of about 450 nm/min with both masks. By adjusting the etch process and depending on the used mask, we tuned the anisotropy from about 19° to 60°. A selectivity of around 4:1 and 1:1 was obtained with SiO2 and photoresist masks, respectively. These results demonstrate how altering the ICP process parameters could affect the etching characteristics and profile.
{"title":"Room temperature inductively coupled plasma etching of InP with Cl2 mixtures using SiO2 and photoresist masks","authors":"Qingyue Li, Claire Deeb, Hélène Debregeas, J. Pelouard","doi":"10.1116/6.0003295","DOIUrl":"https://doi.org/10.1116/6.0003295","url":null,"abstract":"We report the results of a study on the inductively coupled plasma (ICP) etching of InP at room temperature using Cl2 mixtures (Cl2/N2/H2). The impact of different process parameters, including the RF power, the ICP power, the ion-to-neutral ratio, and the chamber pressure, on the etched profile was investigated. The etch rate, selectivity, and anisotropy of the profile were depicted for each etching recipe. Two types of masks, such as SiO2 and AZ5214 photoresist, were used in this study. The etched InP feature showed a very smooth surface (rms as low as 0.5 nm) and a relatively fast etch rate of about 450 nm/min with both masks. By adjusting the etch process and depending on the used mask, we tuned the anisotropy from about 19° to 60°. A selectivity of around 4:1 and 1:1 was obtained with SiO2 and photoresist masks, respectively. These results demonstrate how altering the ICP process parameters could affect the etching characteristics and profile.","PeriodicalId":282302,"journal":{"name":"Journal of Vacuum Science & Technology B","volume":"114 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139837235","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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