Pub Date : 2024-08-29DOI: 10.1088/1361-6463/ad7036
Eunjin Lim, Dahye Kim, Jongmin Park, Minsuk Koo, Sungjun Kim
The increasing demand of information and communication technology has pushed conventional computing paradigm to its limit. In addition, physical and technological factors have constrained the advancement of conventional memory devices. Considering the rapid back-and-forth transfer of a large amount of information, emerging memory should demonstrate space efficiency, fast speed, and low-cost requirements. Accordingly, ferroelectric films based on HfOx are being intensively researched owing to their high energy efficiency and compatibility with complementary metal oxide semiconductor. Particularly, owing to the simplicity of their structure, low power, and less variation, hafnia-based ferroelectric tunnel junctions (FTJs) stand out among ferroelectric memories. Numerous studies have demonstrated the improved ferroelectricity of FTJs using various engineering methods, including doping, annealing, and varying electrodes. To improve the properties of HfOx-based FTJs and enhance their applications, it is necessary to organize and discuss recent studies and prospects. Therefore, this paper reviews in-depth and comprehensive studies on FTJs and their advantages compared to other emerging devices. Additionally, in-memory computing applications, outlook, and challenges of hafnia-based FTJs are presented.
{"title":"Recent advances in the mechanism, properties, and applications of hafnia ferroelectric tunnel junctions","authors":"Eunjin Lim, Dahye Kim, Jongmin Park, Minsuk Koo, Sungjun Kim","doi":"10.1088/1361-6463/ad7036","DOIUrl":"https://doi.org/10.1088/1361-6463/ad7036","url":null,"abstract":"The increasing demand of information and communication technology has pushed conventional computing paradigm to its limit. In addition, physical and technological factors have constrained the advancement of conventional memory devices. Considering the rapid back-and-forth transfer of a large amount of information, emerging memory should demonstrate space efficiency, fast speed, and low-cost requirements. Accordingly, ferroelectric films based on HfO<italic toggle=\"yes\"><sub>x</sub></italic> are being intensively researched owing to their high energy efficiency and compatibility with complementary metal oxide semiconductor. Particularly, owing to the simplicity of their structure, low power, and less variation, hafnia-based ferroelectric tunnel junctions (FTJs) stand out among ferroelectric memories. Numerous studies have demonstrated the improved ferroelectricity of FTJs using various engineering methods, including doping, annealing, and varying electrodes. To improve the properties of HfO<italic toggle=\"yes\"><sub>x</sub></italic>-based FTJs and enhance their applications, it is necessary to organize and discuss recent studies and prospects. Therefore, this paper reviews in-depth and comprehensive studies on FTJs and their advantages compared to other emerging devices. Additionally, in-memory computing applications, outlook, and challenges of hafnia-based FTJs are presented.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"29 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1088/1361-6463/ad6f23
V N Androsenko, M A Kotov, N G Solovyov, A N Shemyakin, M Yu Yakimov
This paper is devoted to the experimental study of the characteristics of a continuous optical discharge (COD) sustained by high power continuous wave laser radiation at a wavelength λ = 1.08 μm in high pressure argon. New data on the COD threshold laser power dependence of argon pressure in the range 20–50 bar is obtained. The COD threshold laser power is shown to be in good agreement with the data obtained by other authors and theoretical evaluations provided the contribution of plasma energy loss due to thermal radiation is taken into account properly. The maximum plasma temperature was estimated to be 20–21 kk or higher, favorable to obtain high UV spectral radiance. A study of the convective plume oscillations around COD in argon has been carried out. It is found that in the pressure range 25–35 bars the growth of the laser radiation power leads to a decrease in convection oscillation frequency from 33 to 29 Hz, while the radius of the convective plume grows accordingly. The oscillation frequency ν and characteristic radius of the convective plume r0 were found to obey the similarity relation ν=0.5g/2r0 previously established in experiments with COD in xenon. These results are promising for using COD in argon as a high brightness broadband UV radiation source.
{"title":"Properties of a continuous optical discharge sustained by short-wave infrared laser radiation in high pressure argon","authors":"V N Androsenko, M A Kotov, N G Solovyov, A N Shemyakin, M Yu Yakimov","doi":"10.1088/1361-6463/ad6f23","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6f23","url":null,"abstract":"This paper is devoted to the experimental study of the characteristics of a continuous optical discharge (COD) sustained by high power continuous wave laser radiation at a wavelength <italic toggle=\"yes\">λ</italic> = 1.08 <italic toggle=\"yes\">μ</italic>m in high pressure argon. New data on the COD threshold laser power dependence of argon pressure in the range 20–50 bar is obtained. The COD threshold laser power is shown to be in good agreement with the data obtained by other authors and theoretical evaluations provided the contribution of plasma energy loss due to thermal radiation is taken into account properly. The maximum plasma temperature was estimated to be 20–21 kk or higher, favorable to obtain high UV spectral radiance. A study of the convective plume oscillations around COD in argon has been carried out. It is found that in the pressure range 25–35 bars the growth of the laser radiation power leads to a decrease in convection oscillation frequency from 33 to 29 Hz, while the radius of the convective plume grows accordingly. The oscillation frequency ν and characteristic radius of the convective plume <italic toggle=\"yes\">r</italic><sub>0</sub> were found to obey the similarity relation <inline-formula>\u0000<tex-math><?CDATA $nu = 0.5sqrt {{g mathord{left/ {vphantom {g {2{r_0}}}} right. } {2{r_0}}}} $?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mi>ν</mml:mi><mml:mo>=</mml:mo><mml:mn>0.5</mml:mn><mml:msqrt><mml:mrow><mml:mi>g</mml:mi><mml:mrow><mml:mo>/</mml:mo></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mrow><mml:msub><mml:mi>r</mml:mi><mml:mn>0</mml:mn></mml:msub></mml:mrow></mml:mrow></mml:mrow></mml:msqrt></mml:mrow></mml:math><inline-graphic xlink:href=\"dad6f23ieqn1.gif\"></inline-graphic></inline-formula> previously established in experiments with COD in xenon. These results are promising for using COD in argon as a high brightness broadband UV radiation source.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"1 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1088/1361-6463/ad6faf
Takahiro Goya, Keiichiro Urabe, Koji Eriguchi
Recently, plasma process-induced damage (PID) has garnered significant interest in the design of thin dielectric films implemented in semiconductor devices. Silicon nitride (SiN) films, a material of interest in strain engineering, are found to suffer from PID because they are exposed to various plasmas during device manufacturing processes. Only a limited amount of experimental evidence is available at present regarding plasma-induced mechanical property changes of SiN films. In this study, we investigated the mechanical property change in SiN and SiO2 films using a cyclic nanoindentation technique. We focused on the contact stiffness (S) as the principal mechanical property parameter. Firstly, a single loading/unloading test confirmed an increase in S after Ar and He plasma exposures. Subsequently, we examined the time-dependent features of damaged SiN and SiO2 films under cyclic loading/unloading. From the cyclic test, an increase in S was seen with the number of loading/unloading cycles (N) for both SiN and SiO2 films. A larger increase in S was observed for the damaged SiN, while no significant increase was seen for the damaged SiO2 films. The observed increase in S and its time dependence are attributed to the strain developed by the created defects (e.g. interstitial species) and the reconstruction and stabilization of plasma-damaged Si–N networks with created defects, respectively. The time-dependent S analysis under cyclic loading/unloading is useful for evaluating the effects of PID on the mechanical properties of thin films.
近来，等离子体过程诱导损伤（PID）在半导体器件薄介质薄膜的设计中引起了极大的关注。氮化硅（SiN）薄膜是应变工程中的一种重要材料，由于在设备制造过程中暴露于各种等离子体中，因此会受到 PID 的影响。目前，有关等离子体诱导氮化硅薄膜机械性能变化的实验证据非常有限。在本研究中，我们使用循环纳米压痕技术研究了 SiN 和 SiO2 薄膜的机械性能变化。我们将接触刚度（S）作为主要的力学性能参数。首先，单次加载/卸载测试证实了在氩和氦等离子体暴露后 S 值的增加。随后，我们研究了在循环加载/卸载下受损的 SiN 和 SiO2 薄膜随时间变化的特征。在循环测试中，SiN 和 SiO2 薄膜的 S 值都随着加载/卸载循环次数（N）的增加而增加。在受损的 SiN 薄膜上观察到的 S 值增幅较大，而在受损的 SiO2 薄膜上则没有观察到明显的增幅。观察到的 S 值增加及其时间依赖性分别归因于产生的缺陷（如间隙物种）所产生的应变，以及等离子体损坏的 Si-N 网络与产生的缺陷的重建和稳定。在循环加载/卸载条件下进行的随时间变化的 S 分析有助于评估 PID 对薄膜机械性能的影响。
{"title":"Evaluation of plasma process-induced mechanical property change in SiN films using a cyclic nanoindentation technique","authors":"Takahiro Goya, Keiichiro Urabe, Koji Eriguchi","doi":"10.1088/1361-6463/ad6faf","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6faf","url":null,"abstract":"Recently, plasma process-induced damage (PID) has garnered significant interest in the design of thin dielectric films implemented in semiconductor devices. Silicon nitride (SiN) films, a material of interest in strain engineering, are found to suffer from PID because they are exposed to various plasmas during device manufacturing processes. Only a limited amount of experimental evidence is available at present regarding plasma-induced mechanical property changes of SiN films. In this study, we investigated the mechanical property change in SiN and SiO<sub>2</sub> films using a cyclic nanoindentation technique. We focused on the contact stiffness (<italic toggle=\"yes\">S</italic>) as the principal mechanical property parameter. Firstly, a single loading/unloading test confirmed an increase in <italic toggle=\"yes\">S</italic> after Ar and He plasma exposures. Subsequently, we examined the time-dependent features of damaged SiN and SiO<sub>2</sub> films under cyclic loading/unloading. From the cyclic test, an increase in <italic toggle=\"yes\">S</italic> was seen with the number of loading/unloading cycles (<italic toggle=\"yes\">N</italic>) for both SiN and SiO<sub>2</sub> films. A larger increase in <italic toggle=\"yes\">S</italic> was observed for the damaged SiN, while no significant increase was seen for the damaged SiO<sub>2</sub> films. The observed increase in <italic toggle=\"yes\">S</italic> and its time dependence are attributed to the strain developed by the created defects (e.g. interstitial species) and the reconstruction and stabilization of plasma-damaged Si–N networks with created defects, respectively. The time-dependent <italic toggle=\"yes\">S</italic> analysis under cyclic loading/unloading is useful for evaluating the effects of PID on the mechanical properties of thin films.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"7 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1088/1361-6463/ad714a
Meize Li, Yahong Liu, Xin Zhou, Lianlian Du, Peng Li, Liyun Tao, Kun Song, Zhenfei Li, Xiaopeng Zhao
Recent works exploiting photonic valley Hall effect show that large-area topological states can be realized by inserting gapless photonic crystal structures into topological interfaces, thus effectively introducing mode width degree of freedom. However, the previously reported works focus on gapless edge states. It is rare to investigate gapped edge states, especially large-area gapped edge states. In this paper, large-area gapped edge states in a valley photonic crystal heterostructure are achieved and experimentally proved. Compared with large-area gapless topological states, the present gapped edge states are more localized, which provides a more effective way to manipulate electromagnetic waves. We implement a topological energy concentrator and topological resonator cavity based on the large-area topological transmission with the gapped edge states. It is expected that our results broaden photonic systems, which can be used in topological lasing, field enhancement, and high-capacity energy transport.
{"title":"Large-area gapped edge states in a valley photonic crystal heterostructure","authors":"Meize Li, Yahong Liu, Xin Zhou, Lianlian Du, Peng Li, Liyun Tao, Kun Song, Zhenfei Li, Xiaopeng Zhao","doi":"10.1088/1361-6463/ad714a","DOIUrl":"https://doi.org/10.1088/1361-6463/ad714a","url":null,"abstract":"Recent works exploiting photonic valley Hall effect show that large-area topological states can be realized by inserting gapless photonic crystal structures into topological interfaces, thus effectively introducing mode width degree of freedom. However, the previously reported works focus on gapless edge states. It is rare to investigate gapped edge states, especially large-area gapped edge states. In this paper, large-area gapped edge states in a valley photonic crystal heterostructure are achieved and experimentally proved. Compared with large-area gapless topological states, the present gapped edge states are more localized, which provides a more effective way to manipulate electromagnetic waves. We implement a topological energy concentrator and topological resonator cavity based on the large-area topological transmission with the gapped edge states. It is expected that our results broaden photonic systems, which can be used in topological lasing, field enhancement, and high-capacity energy transport.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"12 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1088/1361-6463/ad7039
Nicola Roccato, Francesco Piva, Matteo Buffolo, Carlo De Santi, Nicola Trivellin, Camille Haller, Jean-François Carlin, Nicolas Grandjean, Gaudenzio Meneghesso, Enrico Zanoni, Matteo Meneghini
We investigate the degradation mechanisms of In0.2Ga0.8N/GaN light emitting diodes through combined experimental analysis and simulations. The devices were submitted to constant current stress at 100 mA. Depending on the measuring current level, two degradation trends were observed: at high test currents (e.g. 200 mA), a monotonic decrease in optical power was observed; at low test currents (e.g. 5 mA), an initial degradation was observed, followed by an improvement in device efficiency (positive ageing). For the first time, such recovery effect was analyzed and modeled, as due to the generation of charged defects at the InGaN/GaN interface, resulting in the increase in the injection efficiency at low bias levels. The role of interface defects was validated by means of numerical simulations, with good agreement with the experimental data.
{"title":"Investigation and modeling of the role of interface defects in the optical degradation of InGaN/GaN LEDs","authors":"Nicola Roccato, Francesco Piva, Matteo Buffolo, Carlo De Santi, Nicola Trivellin, Camille Haller, Jean-François Carlin, Nicolas Grandjean, Gaudenzio Meneghesso, Enrico Zanoni, Matteo Meneghini","doi":"10.1088/1361-6463/ad7039","DOIUrl":"https://doi.org/10.1088/1361-6463/ad7039","url":null,"abstract":"We investigate the degradation mechanisms of In<sub>0.2</sub>Ga<sub>0.8</sub>N/GaN light emitting diodes through combined experimental analysis and simulations. The devices were submitted to constant current stress at 100 mA. Depending on the measuring current level, two degradation trends were observed: at high test currents (e.g. 200 mA), a monotonic decrease in optical power was observed; at low test currents (e.g. 5 mA), an initial degradation was observed, followed by an improvement in device efficiency (positive ageing). For the first time, such recovery effect was analyzed and modeled, as due to the generation of charged defects at the InGaN/GaN interface, resulting in the increase in the injection efficiency at low bias levels. The role of interface defects was validated by means of numerical simulations, with good agreement with the experimental data.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"5 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1088/1361-6463/ad6fac
Hongsheng Zhai, Man Liu, Endong Wang, Yufang Liu
The growth mechanism of thiolate-protected gold nanoclusters (AuNCs) has been advanced, but precise crystal structure information is lacking. Recent mass spectrometry and nuclear magnetic resonance analysis experiments traced the Au24(SR)18 cluster as a non-negligible byproduct intermediate during the reaction between [Au25(SR)18]−, the flagship cluster of the remarkable nanocluster ship, and Au25(SR)19, a cluster with 25 Au atoms but featuring a completely different structure than the [Au25(SR)18]− cluster. However, the precise structure of the Au24(SR)18 cluster is unknown. In this study, a total of seven Au24(SR)18 isomers were constructed using the grand unified model. Density functional theory calculations demonstrated that two of them could be considered quasi-degenerate suggesting that both might coexist in experiments. Geometrical features, electronic structures, and absorption spectra were calculated for potential future comparisons. This work contributes to fully interpreting the growth mechanism of AuNCs .
{"title":"Rational design of the 6e thiolate-protected Au24(SR)18 nanocluster","authors":"Hongsheng Zhai, Man Liu, Endong Wang, Yufang Liu","doi":"10.1088/1361-6463/ad6fac","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6fac","url":null,"abstract":"The growth mechanism of thiolate-protected gold nanoclusters (AuNCs) has been advanced, but precise crystal structure information is lacking. Recent mass spectrometry and nuclear magnetic resonance analysis experiments traced the Au<sub>24</sub>(SR)<sub>18</sub> cluster as a non-negligible byproduct intermediate during the reaction between [Au<sub>25</sub>(SR)<sub>18</sub>]<sup>−</sup>, the flagship cluster of the remarkable nanocluster ship, and Au<sub>25</sub>(SR)<sub>19</sub>, a cluster with 25 Au atoms but featuring a completely different structure than the [Au<sub>25</sub>(SR)<sub>18</sub>]<sup>−</sup> cluster. However, the precise structure of the Au<sub>24</sub>(SR)<sub>18</sub> cluster is unknown. In this study, a total of seven Au<sub>24</sub>(SR)<sub>18</sub> isomers were constructed using the grand unified model. Density functional theory calculations demonstrated that two of them could be considered quasi-degenerate suggesting that both might coexist in experiments. Geometrical features, electronic structures, and absorption spectra were calculated for potential future comparisons. This work contributes to fully interpreting the growth mechanism of AuNCs .","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"22 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nanoscale vacuum channel transistors (NVCTs) have garnered considerable interest due to their outstanding high frequency characteristics and high reliability, stemming from a distinct carrier transport mechanism compared to solid-state devices. Electrons traverse the nanoscale vacuum channel through scattering-free ballistic transport. However, existing research has predominantly focused on the structural design and optimization of NVCTs, with relatively few studies delving into their high frequency performance. Hence, alongside structural exploration and optimizing, investigating the high-frequency characteristics of NVCTs assumes particular importance. In this study, a novel NVCTs with a gate-cathode height difference structure was proposed and its electrical characteristics were simulated. Simulation results reveal that the presence of gate-cathode height difference effectively enhance the DC characteristics of NVCTs. Moreover, high frequency simulation demonstrate that the proposed device can operate frequency exceeding 1 THz. Whitin the GHz and even terahertz (THz) range, NVCTs exhibits exceptional high frequency properties, including ultrafast response times and minimal distortion. These findings not only offer insights for future structural design and optimization of NVCTs but also underscore the potential of NVCTs in radio frequency and THz applications.
{"title":"High-frequency performance in nanoscale vacuum channel transistors with gate-cathode height difference","authors":"Yuezhong Chen, Xin Zhai, Congyuan Lin, Ziyang Liu, Xiaobing Zhang, Ji Xu","doi":"10.1088/1361-6463/ad70c2","DOIUrl":"https://doi.org/10.1088/1361-6463/ad70c2","url":null,"abstract":"Nanoscale vacuum channel transistors (NVCTs) have garnered considerable interest due to their outstanding high frequency characteristics and high reliability, stemming from a distinct carrier transport mechanism compared to solid-state devices. Electrons traverse the nanoscale vacuum channel through scattering-free ballistic transport. However, existing research has predominantly focused on the structural design and optimization of NVCTs, with relatively few studies delving into their high frequency performance. Hence, alongside structural exploration and optimizing, investigating the high-frequency characteristics of NVCTs assumes particular importance. In this study, a novel NVCTs with a gate-cathode height difference structure was proposed and its electrical characteristics were simulated. Simulation results reveal that the presence of gate-cathode height difference effectively enhance the DC characteristics of NVCTs. Moreover, high frequency simulation demonstrate that the proposed device can operate frequency exceeding 1 THz. Whitin the GHz and even terahertz (THz) range, NVCTs exhibits exceptional high frequency properties, including ultrafast response times and minimal distortion. These findings not only offer insights for future structural design and optimization of NVCTs but also underscore the potential of NVCTs in radio frequency and THz applications.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"4 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1088/1361-6463/ad7151
Shimin Yu, Zili Chen, Jingwen Xu, Hongyu Wang, Lu Wang, Zhijiang Wang, Wei Jiang, Julian Schulze, Ya Zhang
Capacitively coupled plasmas (CCPs) are widely used in plasma processing applications, where efficient power coupling between the radio frequency (RF) source and the plasma is crucial. In practical CCP systems, impedance matching networks (IMNs) are employed to minimize power reflection. However, the presence of coaxial cables can significantly impact plasma impedance and matching performance. We develop a comprehensive simulation framework for the IMN design of CCPs, fully considering the effects of RF coaxial cables. The model self-consistently couples a distributed transmission line (TL) model, a lumped-element circuit model, and an electrostatic particle-in-cell model. This coupled model is used to investigate the impact of coaxial cables on matching performance under various discharge conditions and cable configurations. The simulation results indicate that the optimal power transmission efficiency was achieved after 6 matching iterations. The power coupled to the CCP increased from 2.7 W before matching to 180.9 W, and the reflection coefficient ultimately decreased to 0.003. The results also reveal that neglecting the cables will lead to a decrease in the power dissipated in the CCP. The proposed method demonstrates effectiveness in achieving impedance matching for different gas pressures (75–300 mTorr) and cable lengths. It can be concluded that the matching speed is faster for an appropriate cable length. This work provides valuable insights into the role of TLs in CCP impedance matching and offers a practical tool for optimizing power delivery in realistic CCP systems with RF coaxial cables.
{"title":"Impedance matching design for capacitively coupled plasmas considering coaxial cables","authors":"Shimin Yu, Zili Chen, Jingwen Xu, Hongyu Wang, Lu Wang, Zhijiang Wang, Wei Jiang, Julian Schulze, Ya Zhang","doi":"10.1088/1361-6463/ad7151","DOIUrl":"https://doi.org/10.1088/1361-6463/ad7151","url":null,"abstract":"Capacitively coupled plasmas (CCPs) are widely used in plasma processing applications, where efficient power coupling between the radio frequency (RF) source and the plasma is crucial. In practical CCP systems, impedance matching networks (IMNs) are employed to minimize power reflection. However, the presence of coaxial cables can significantly impact plasma impedance and matching performance. We develop a comprehensive simulation framework for the IMN design of CCPs, fully considering the effects of RF coaxial cables. The model self-consistently couples a distributed transmission line (TL) model, a lumped-element circuit model, and an electrostatic particle-in-cell model. This coupled model is used to investigate the impact of coaxial cables on matching performance under various discharge conditions and cable configurations. The simulation results indicate that the optimal power transmission efficiency was achieved after 6 matching iterations. The power coupled to the CCP increased from 2.7 W before matching to 180.9 W, and the reflection coefficient ultimately decreased to 0.003. The results also reveal that neglecting the cables will lead to a decrease in the power dissipated in the CCP. The proposed method demonstrates effectiveness in achieving impedance matching for different gas pressures (75–300 mTorr) and cable lengths. It can be concluded that the matching speed is faster for an appropriate cable length. This work provides valuable insights into the role of TLs in CCP impedance matching and offers a practical tool for optimizing power delivery in realistic CCP systems with RF coaxial cables.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"13 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1088/1361-6463/ad6a25
Liu Liu, Anding Li, Yukun Chen, Ruirui Liu, Jiayue Xu, Jiwei Zhai, Zhitang Song and Sannian Song
This study investigates the phase-change properties of [Ge8Sb92 (25 nm)-Ge2Sb2Te5 (25 nm)]1 multilayer thin films, elucidating three distinct resistance states originating from two structural transitions: initial Sb precipitation and Ge2Sb2Te5-FCC crystallization, followed by Ge2Sb2Te5-FCC to Ge2Sb2Te5-HEX transformation with additional Sb precipitation. The phase transitions induce two abrupt changes in resistance at temperatures of 169.8 °C and 197.7 °C, respectively, with corresponding data retention temperatures of 97 °C and 129 °C, indicating robust thermal stability. The [Ge8Sb92 (25 nm)-Ge2Sb2Te5 (25 nm)]1-based phase change random access memory (PCRAM) device demonstrates reversible switching characteristics and multi-level storage capabilities within 20 ns, showcasing enhanced phase-change speed and storage density. In summary, [Ge8Sb92(25 nm)-Ge2Sb2Te5(25 nm)]1 demonstrates enhanced thermal stability, swift phase transition, and increased storage density relative to conventional Ge2Sb2Te5, establishing it as a promising new phase-change material for PCRAM applications.
{"title":"Multilayer Ge8Sb92/Ge2Sb2Te5 thin films: unveiling distinct resistance states and enhanced performance for phase change random access memory","authors":"Liu Liu, Anding Li, Yukun Chen, Ruirui Liu, Jiayue Xu, Jiwei Zhai, Zhitang Song and Sannian Song","doi":"10.1088/1361-6463/ad6a25","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6a25","url":null,"abstract":"This study investigates the phase-change properties of [Ge8Sb92 (25 nm)-Ge2Sb2Te5 (25 nm)]1 multilayer thin films, elucidating three distinct resistance states originating from two structural transitions: initial Sb precipitation and Ge2Sb2Te5-FCC crystallization, followed by Ge2Sb2Te5-FCC to Ge2Sb2Te5-HEX transformation with additional Sb precipitation. The phase transitions induce two abrupt changes in resistance at temperatures of 169.8 °C and 197.7 °C, respectively, with corresponding data retention temperatures of 97 °C and 129 °C, indicating robust thermal stability. The [Ge8Sb92 (25 nm)-Ge2Sb2Te5 (25 nm)]1-based phase change random access memory (PCRAM) device demonstrates reversible switching characteristics and multi-level storage capabilities within 20 ns, showcasing enhanced phase-change speed and storage density. In summary, [Ge8Sb92(25 nm)-Ge2Sb2Te5(25 nm)]1 demonstrates enhanced thermal stability, swift phase transition, and increased storage density relative to conventional Ge2Sb2Te5, establishing it as a promising new phase-change material for PCRAM applications.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"61 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1088/1361-6463/ad6a23
Na Xiao, Vishal Khandelwal, Saravanan Yuvaraja, Dhanu Chettri, Genesh Mainali, Zhiyuan Liu, Mohamed Ben Hassine, Xiao Tang and Xiaohang Li
Here, we demonstrate a high-mobility indium oxide (In2O3) thin-film transistor (TFT) with a sputtered alumina (Al2O3) passivation layer (PVL) with a low thermal budget (200 °C). The sputtering process of the Al2O3 PVL plays a positive role in improving the field-effect mobility (µFE) and current on/off ratio (ION/IOFF) performance of the In2O3 TFTs. However, these enhancements are limited due to the high density of intrinsic trap defects in the In2O3 channels, as reflected in their large hysteresis and poor bias stability. Treating the In2O3 channel with oxygen (O2) plasma prior to sputtering the Al2O3 PVL results in notable improvements. Specifically, a high µFE of 128.3 cm2V−1 s−1, a high ION/IOFF over 106 at VDS of 0.1 V, a small hysteresis of 0.03 V, and a negligible threshold voltage shift under negative bias stress are achieved in the passivated In2O3 TFT (with O2 plasma pretreatment), representing a significant improvement compared to the passivated In2O3 TFT (without O2 plasma pretreatment) and the unpassivated In2O3 TFT. The remarkable reduction of intrinsic trap defects in the passivated In2O3 TFT compensated by O2 plasma is the primary mechanism underlying the improvement in µFE and bias stability, as validated by x-ray photoelectron spectra, hysteresis analysis, and temperature-stress electrical characterizations. Plasma treatment effectively compensates for intrinsic trap defects in oxide semiconductor (OS) channels, when combined with sputter passivation, resulting in a significant enhancement of the overall performance of OS TFTs under low thermal budgets. This approach offers valuable insights into advancing OS TFTs with satisfactory driving capability and wide applicability.
{"title":"Passivated indium oxide thin-film transistors with high field-effect mobility (128.3 cm2 V−1 s−1) and low thermal budget (200 °C)","authors":"Na Xiao, Vishal Khandelwal, Saravanan Yuvaraja, Dhanu Chettri, Genesh Mainali, Zhiyuan Liu, Mohamed Ben Hassine, Xiao Tang and Xiaohang Li","doi":"10.1088/1361-6463/ad6a23","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6a23","url":null,"abstract":"Here, we demonstrate a high-mobility indium oxide (In2O3) thin-film transistor (TFT) with a sputtered alumina (Al2O3) passivation layer (PVL) with a low thermal budget (200 °C). The sputtering process of the Al2O3 PVL plays a positive role in improving the field-effect mobility (µFE) and current on/off ratio (ION/IOFF) performance of the In2O3 TFTs. However, these enhancements are limited due to the high density of intrinsic trap defects in the In2O3 channels, as reflected in their large hysteresis and poor bias stability. Treating the In2O3 channel with oxygen (O2) plasma prior to sputtering the Al2O3 PVL results in notable improvements. Specifically, a high µFE of 128.3 cm2V−1 s−1, a high ION/IOFF over 106 at VDS of 0.1 V, a small hysteresis of 0.03 V, and a negligible threshold voltage shift under negative bias stress are achieved in the passivated In2O3 TFT (with O2 plasma pretreatment), representing a significant improvement compared to the passivated In2O3 TFT (without O2 plasma pretreatment) and the unpassivated In2O3 TFT. The remarkable reduction of intrinsic trap defects in the passivated In2O3 TFT compensated by O2 plasma is the primary mechanism underlying the improvement in µFE and bias stability, as validated by x-ray photoelectron spectra, hysteresis analysis, and temperature-stress electrical characterizations. Plasma treatment effectively compensates for intrinsic trap defects in oxide semiconductor (OS) channels, when combined with sputter passivation, resulting in a significant enhancement of the overall performance of OS TFTs under low thermal budgets. This approach offers valuable insights into advancing OS TFTs with satisfactory driving capability and wide applicability.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"25 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","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：