Pub Date : 2024-04-08DOI: 10.1109/OJNANO.2024.3386123
Muhammad Aslam;Shu-Wei Chang;Min-Hui Chuang;Yi-Ho Chen;Yao-Jen Lee;Yiming Li
Recently, a-IGZO has advanced toward the next-generation electronics system because of its compatibility with complementary metal oxide semiconductor (CMOS) and back-end-of-line (BOEL) based systems. A systematic electrical characterization of a-IGZO TFT related to reliability issues, such as positive bias temperature stress (PBTS) and negative bias temperature stress (NBTS), would entitle its integration into novel electronics systems. Unexpectedly, PBTS is characterized by the transition of positive V th shift to negative V th shift (ΔV th , the positive shift followed by the stress and temperature activated negative shift). This transition is attributed to charge trapping/trap-site generations and hydrogen migration to the active layer. The ΔV th shift mechanism depends on the temperature and voltage stress. On the other hand, a negative ΔV th shift has been observed during the NBTS operation and could be attributed to the hole trapping at the interface of GI/IGZO. An effective suppression of the gate leakage current has also been observed during reliability tests. Simulation results reveal a pronounced potential at the edges of source and drain regions, and considered the origin of hydrogen migration into the IGZO layer. Thermal image results also reveal the strong temperature/potential distribution at the edges of the source/drain regions, indorsing the simulation results.
{"title":"Temperature-Dependent Hydrogen Modulations of Ultra-Scaled a-IGZO Thin Film Transistor Under Gate Bias Stress","authors":"Muhammad Aslam;Shu-Wei Chang;Min-Hui Chuang;Yi-Ho Chen;Yao-Jen Lee;Yiming Li","doi":"10.1109/OJNANO.2024.3386123","DOIUrl":"10.1109/OJNANO.2024.3386123","url":null,"abstract":"Recently, a-IGZO has advanced toward the next-generation electronics system because of its compatibility with complementary metal oxide semiconductor (CMOS) and back-end-of-line (BOEL) based systems. A systematic electrical characterization of a-IGZO TFT related to reliability issues, such as positive bias temperature stress (PBTS) and negative bias temperature stress (NBTS), would entitle its integration into novel electronics systems. Unexpectedly, PBTS is characterized by the transition of positive V\u0000<sub>th</sub>\u0000 shift to negative V\u0000<sub>th</sub>\u0000 shift (ΔV\u0000<sub>th</sub>\u0000, the positive shift followed by the stress and temperature activated negative shift). This transition is attributed to charge trapping/trap-site generations and hydrogen migration to the active layer. The ΔV\u0000<sub>th</sub>\u0000 shift mechanism depends on the temperature and voltage stress. On the other hand, a negative ΔV\u0000<sub>th</sub>\u0000 shift has been observed during the NBTS operation and could be attributed to the hole trapping at the interface of GI/IGZO. An effective suppression of the gate leakage current has also been observed during reliability tests. Simulation results reveal a pronounced potential at the edges of source and drain regions, and considered the origin of hydrogen migration into the IGZO layer. Thermal image results also reveal the strong temperature/potential distribution at the edges of the source/drain regions, indorsing the simulation results.","PeriodicalId":446,"journal":{"name":"IEEE Open Journal of Nanotechnology","volume":"5 ","pages":"9-16"},"PeriodicalIF":1.7,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10494359","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140563451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-10DOI: 10.1109/OJNANO.2024.3399559
Heng Li Lin;Pin Su
Using extensive Monte-Carlo simulations with a nucleation-limited-switching (NLS) ferroelectric model and considering cycle-to-cycle variations, this paper constructs and analyzes the intrinsic conductance (G DS ) response of stacked-nanosheet FeFET synapses with emphasis on the challenging identical-pulse stimulation. Our study indicates that the interlayer oxide thickness of the FeFET and the saturation polarization of the ferroelectric are crucial to the linearity and symmetry of the intrinsic G DS response. With the stacked-nanosheet architecture, the maximum-to-minimum conductance ratio in the G DS response can be boosted by increasing the number of channel tiers without footprint penalty. For a stacked-nanosheet FeFET synapse with an area ratio effect, the G DS response can be further engineered by varying the tier number. In addition, the immunity to cycle-to-cycle variations and the noise margin for each state in the G DS response can also be improved by increasing the number of tiers. Our study may provide insights for future FeFET synapse design for analog computing.
{"title":"Analysis and Design of FeFET Synapse With Stacked-Nanosheet Architecture Considering Cycle-to-Cycle Variations for Neuromorphic Applications","authors":"Heng Li Lin;Pin Su","doi":"10.1109/OJNANO.2024.3399559","DOIUrl":"10.1109/OJNANO.2024.3399559","url":null,"abstract":"Using extensive Monte-Carlo simulations with a nucleation-limited-switching (NLS) ferroelectric model and considering cycle-to-cycle variations, this paper constructs and analyzes the intrinsic conductance (G\u0000<sub>DS</sub>\u0000) response of stacked-nanosheet FeFET synapses with emphasis on the challenging identical-pulse stimulation. Our study indicates that the interlayer oxide thickness of the FeFET and the saturation polarization of the ferroelectric are crucial to the linearity and symmetry of the intrinsic G\u0000<sub>DS</sub>\u0000 response. With the stacked-nanosheet architecture, the maximum-to-minimum conductance ratio in the G\u0000<sub>DS</sub>\u0000 response can be boosted by increasing the number of channel tiers without footprint penalty. For a stacked-nanosheet FeFET synapse with an area ratio effect, the G\u0000<sub>DS</sub>\u0000 response can be further engineered by varying the tier number. In addition, the immunity to cycle-to-cycle variations and the noise margin for each state in the G\u0000<sub>DS</sub>\u0000 response can also be improved by increasing the number of tiers. Our study may provide insights for future FeFET synapse design for analog computing.","PeriodicalId":446,"journal":{"name":"IEEE Open Journal of Nanotechnology","volume":"5 ","pages":"17-22"},"PeriodicalIF":1.7,"publicationDate":"2024-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10528861","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140941427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-06DOI: 10.1109/OJNANO.2024.3362551
{"title":"IEEE Open Journal of Nanotechnology Information for Authors","authors":"","doi":"10.1109/OJNANO.2024.3362551","DOIUrl":"https://doi.org/10.1109/OJNANO.2024.3362551","url":null,"abstract":"","PeriodicalId":446,"journal":{"name":"IEEE Open Journal of Nanotechnology","volume":"5 ","pages":"C3-C3"},"PeriodicalIF":1.7,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10461135","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140052994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This research focuses on a quantum model created using an entirely novel nanosheet FET. The standard model describes the performance of a Gate-all-around (GAA) Junction-less (JL) nanosheet device with a gate dielectric of SiO 2 and HfO 2 , each having a thickness of 1 nm. The performance of both the classical and quantum models of the GAA nanosheet device is evaluated using the visual TCAD tool, which measures the ION , IOFF , ION/ IOFF , threshold voltage, DIBL, gain parameters (g m , g d , A v ), gate capacitance, and cut-off frequency ( fT ). The device is suited for applications needing rapid switching since it has a low gate capacitance of the order of 10 –18 , according to the simulation results. A transconductance (g m ) value of 21 µS and an impressive cut-off frequency of 9.03 GHz are displayed during device analysis. A detailed investigation has also been done into the P-type device response for the same device. Finally, the proposed GAA nanosheet device is used in the inverter model. The NSFET-based inverter, although having higher gate capacitance, has the shortest propagation latency.
{"title":"Analysis of GAA Junction Less NS FET Towards Analog and RF Applications at 30 nm Regime","authors":"Asisa Kumar Panigrahy;Sudheer Hanumanthakari;Shridhar B. Devamane;Shruti Bhargava Choubey;M. Prasad;D. Somasundaram;N. Kumareshan;N. Arun Vignesh;Gnanasaravanan Subramaniam;Durga Prakash M;Raghunandan Swain","doi":"10.1109/OJNANO.2024.3365173","DOIUrl":"10.1109/OJNANO.2024.3365173","url":null,"abstract":"This research focuses on a quantum model created using an entirely novel nanosheet FET. The standard model describes the performance of a Gate-all-around (GAA) Junction-less (JL) nanosheet device with a gate dielectric of SiO\u0000<sub>2</sub>\u0000 and HfO\u0000<sub>2</sub>\u0000, each having a thickness of 1 nm. The performance of both the classical and quantum models of the GAA nanosheet device is evaluated using the visual TCAD tool, which measures the \u0000<italic>I<sub>ON</sub></i>\u0000, \u0000<italic>I<sub>OFF</sub></i>\u0000, \u0000<italic>I<sub>ON</sub>/ I<sub>OFF</sub></i>\u0000, threshold voltage, DIBL, gain parameters (g\u0000<sub>m</sub>\u0000, g\u0000<sub>d</sub>\u0000, A\u0000<sub>v</sub>\u0000), gate capacitance, and cut-off frequency (\u0000<italic>f<sub>T</sub></i>\u0000). The device is suited for applications needing rapid switching since it has a low gate capacitance of the order of 10\u0000<sup>–18</sup>\u0000, according to the simulation results. A transconductance (g\u0000<sub>m</sub>\u0000) value of 21 µS and an impressive cut-off frequency of 9.03 GHz are displayed during device analysis. A detailed investigation has also been done into the P-type device response for the same device. Finally, the proposed GAA nanosheet device is used in the inverter model. The NSFET-based inverter, although having higher gate capacitance, has the shortest propagation latency.","PeriodicalId":446,"journal":{"name":"IEEE Open Journal of Nanotechnology","volume":"5 ","pages":"1-8"},"PeriodicalIF":1.7,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10433722","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139946923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-28DOI: 10.1109/OJNANO.2023.3335942
Sekhar Reddy Kola;Yiming Li
Characteristic variability induced by process variation effect (PVE) is one of technological challenges in semiconductor industry. In this work, we computationally study electrical characteristic and power fluctuations induced by six factors of PVE of the gate-all-around (GAA) silicon (Si) nanosheet (NS) complementary field-effect-transistors (CFETs) which are formed by vertically stacking n -FET on top of p -FET. Among the six factors, NS thickness ( TNS ), NS width ( WNS ), and gate length ( LG ) are identified as crucial factors contributing to large variations in device characteristics. The p -FET exhibits substantial off-state current fluctuation (about 151%) due to the bottom parasitic channel leakages. Compared with the magnitudes of dynamic and short circuit powers, the static power is marginal, but it possesses the largest fluctuation (up to 148%). If we assume that each factor of PVE has the same probability distribution as the others and all are mutually independent, the statistical sum of their power fluctuations will exhibit more than 50% overestimations, compared with the results when all factors are considered simultaneously.
工艺变异效应（PVE）引起的特性变化是半导体行业面临的技术挑战之一。在这项工作中，我们通过计算研究了在 p 型场效应晶体管上垂直堆叠 n 型场效应晶体管而形成的全栅极（GAA）硅（Si）纳米片（NS）互补场效应晶体管（CFET）的六个 PVE 因素引起的电气特性和功率波动。在这六个因素中，NS 厚度 (TNS)、NS 宽度 (WNS) 和栅极长度 (LG) 被认为是导致器件特性发生巨大变化的关键因素。由于底部寄生沟道泄漏，p-场效应晶体管表现出很大的关态电流波动（约 151%）。与动态功率和短路功率的大小相比，静态功率微不足道，但波动却最大（高达 148%）。如果我们假设 PVE 的每个因素与其他因素具有相同的概率分布，并且所有因素都相互独立，那么与同时考虑所有因素时的结果相比，其功率波动的统计总和将高估 50%以上。
{"title":"Electrical Characteristic and Power Fluctuations of GAA Si NS CFETs by Simultaneously Considering Six Process Variation Factors","authors":"Sekhar Reddy Kola;Yiming Li","doi":"10.1109/OJNANO.2023.3335942","DOIUrl":"https://doi.org/10.1109/OJNANO.2023.3335942","url":null,"abstract":"Characteristic variability induced by process variation effect (PVE) is one of technological challenges in semiconductor industry. In this work, we computationally study electrical characteristic and power fluctuations induced by six factors of PVE of the gate-all-around (GAA) silicon (Si) nanosheet (NS) complementary field-effect-transistors (CFETs) which are formed by vertically stacking \u0000<italic>n</i>\u0000-FET on top of \u0000<italic>p</i>\u0000-FET. Among the six factors, NS thickness (\u0000<italic>T<sub>NS</sub></i>\u0000), NS width (\u0000<italic>W<sub>NS</sub></i>\u0000), and gate length (\u0000<italic>L<sub>G</sub></i>\u0000) are identified as crucial factors contributing to large variations in device characteristics. The \u0000<italic>p</i>\u0000-FET exhibits substantial off-state current fluctuation (about 151%) due to the bottom parasitic channel leakages. Compared with the magnitudes of dynamic and short circuit powers, the static power is marginal, but it possesses the largest fluctuation (up to 148%). If we assume that each factor of PVE has the same probability distribution as the others and all are mutually independent, the statistical sum of their power fluctuations will exhibit more than 50% overestimations, compared with the results when all factors are considered simultaneously.","PeriodicalId":446,"journal":{"name":"IEEE Open Journal of Nanotechnology","volume":"4 ","pages":"229-238"},"PeriodicalIF":1.7,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10330087","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138739547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-24DOI: 10.1109/OJNANO.2023.3336366
Kamal Solanki;Swati Verma;Punya Prasanna Paltani;Manoj Kumar Majumder
Elevated Particular Matter (PM 2.5 ) may increase the risk of acquiring hazardous health implications, and hence high-performance monitoring of minuscule contaminants might protect people's health. The adsorption behaviour of specific PM 2.5 contaminants on doped/undoped monolayer/bilayer armchair graphene nanoribbon (ArGNR) is analyzed using a hydrogen-passivated layer. By using the first-principles density functional theory (DFT), the influence of doping on the ArGNR substrate is carefully examined. Due to the fragile surface atoms, monolayer ArGNR exhibits roughly twice the adsorption energy compared to the bilayer configuration. However, the specific PM 2.5 contaminants, the CH 4 , NH 3 , and NO 2 molecules demonstrate chemisorption of −2 eV,−2.95 eV, and −4 eV, with extremely less bandgap variation of −65% to −70% and −100% and a gigantic amount of charge transfer of +0.153 eV, +0.156 eV and +0.010 eV, and the DOS peaks at B site are $ pm 110,text{eV}, pm 65{rm{ eV}}, pm 80{rm{ eV}}$ , and at the P site are $ pm 130$ eV, $ pm 300$ eV and $ pm 80$ eV on boron-phosphorus (BP) co-doped monolayer ArGNR, for CH 4 , NH 3, and NO 2 , respectively.
高浓度的微粒物质（PM2.5）可能会增加人们获得有害健康影响的风险，因此对微小污染物的高性能监测可能会保护人们的健康。本研究利用氢钝化层分析了特定 PM2.5 污染物在掺杂/未掺杂单层/双层臂向石墨烯纳米带（ArGNR）上的吸附行为。通过使用第一原理密度泛函理论（DFT），仔细研究了掺杂对 ArGNR 衬底的影响。由于表面原子比较脆弱，单层 ArGNR 的吸附能大约是双层结构的两倍。然而，特定的 PM2.5 污染物、CH4、NH3 和 NO2 分子的化学吸附能分别为 -2 eV、-2.95 eV 和 -4 eV，带隙变化极小，分别为 -65% 至 -70% 和 -100%，电荷转移量极大，分别为 +0.153 eV、+0.156 eV 和 +0.010 eV，在硼磷（BP）共掺杂单层 ArGNR 上，CH4、NH3 和 NO2 在 B 位的 DOS 峰分别为 $pm 110,text{eV}, pm 65{rm{ eV}}, pm 80{rm{ eV}}$ ，在 P 位的 DOS 峰分别为 $pm 130$ eV, $pm 300$ eV 和 $pm 80$ eV。
{"title":"Impact of Specific PM2.5 Contaminant on Monolayer/Bilayer ArGNR","authors":"Kamal Solanki;Swati Verma;Punya Prasanna Paltani;Manoj Kumar Majumder","doi":"10.1109/OJNANO.2023.3336366","DOIUrl":"https://doi.org/10.1109/OJNANO.2023.3336366","url":null,"abstract":"Elevated Particular Matter (PM\u0000<sub>2.5</sub>\u0000) may increase the risk of acquiring hazardous health implications, and hence high-performance monitoring of minuscule contaminants might protect people's health. The adsorption behaviour of specific PM\u0000<sub>2.5</sub>\u0000 contaminants on doped/undoped monolayer/bilayer armchair graphene nanoribbon (ArGNR) is analyzed using a hydrogen-passivated layer. By using the first-principles density functional theory (DFT), the influence of doping on the ArGNR substrate is carefully examined. Due to the fragile surface atoms, monolayer ArGNR exhibits roughly twice the adsorption energy compared to the bilayer configuration. However, the specific PM\u0000<sub>2.5</sub>\u0000 contaminants, the CH\u0000<sub>4</sub>\u0000, NH\u0000<sub>3</sub>\u0000, and NO\u0000<sub>2</sub>\u0000 molecules demonstrate chemisorption of −2 eV,−2.95 eV, and −4 eV, with extremely less bandgap variation of −65% to −70% and −100% and a gigantic amount of charge transfer of +0.153 eV, +0.156 eV and +0.010 eV, and the DOS peaks at B site are \u0000<inline-formula><tex-math>$ pm 110,text{eV}, pm 65{rm{ eV}}, pm 80{rm{ eV}}$</tex-math></inline-formula>\u0000, and at the P site are \u0000<inline-formula><tex-math>$ pm 130$</tex-math></inline-formula>\u0000 eV, \u0000<inline-formula><tex-math>$ pm 300$</tex-math></inline-formula>\u0000 eV and \u0000<inline-formula><tex-math>$ pm 80$</tex-math></inline-formula>\u0000 eV on boron-phosphorus (BP) co-doped monolayer ArGNR, for CH\u0000<sub>4</sub>\u0000, NH\u0000<sub>3,</sub>\u0000 and NO\u0000<sub>2</sub>\u0000, respectively.","PeriodicalId":446,"journal":{"name":"IEEE Open Journal of Nanotechnology","volume":"4 ","pages":"215-228"},"PeriodicalIF":1.7,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10328676","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138558073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-10DOI: 10.1109/OJNANO.2023.3331974
Zitao Tang;Siwei Chen;Cynthia I. Osuala;Abdus Salam Sarkar;Grzegorz Hader;Aron Cummings;Stefan Strauf;Chunlei Qu;Eui-Hyeok Yang
We present the observations of Aharonov-Bohm (AB) oscillations in chemical vapor deposition (CVD)-grown graphene rings via magnetotransport measurements at 4K under out-of-plane external magnetic fields up to +/−2.1 T. Incorporating a baseline subtraction of the original conductance data allowed us to observe two-terminal conductance oscillations with a spacing of ΔB AB of 3.66 to 32.9 mT from the ring with an inner radius of 200 nm and arm-width of 400 nm, and spacing of ΔB AB from 2.1 mT to 8.2 mT from the ring with an inner radius of 400 nm and an arm-width of 400 nm. The fast-Fourier transform (FFT) data showed AB oscillation periods, with the interval of the h/e fundamental mode given by 30/T to 273/T for the ring with the inner radius of 200 nm and arm-width of 400 nm, and 122/T to 488/T for the ring with the inner radius of 400 nm. The broad spreading of FFT peaks is due to the aspect ratio of the inner radius r1 and the width w of the ring, r/w ∼ 1. Systematic numerical simulations were performed to elucidate the relation between the AB oscillation frequency and the geometry of the ring. This work shows AB oscillations in CVD-grown graphene rings at an elevated temperature (4K).
{"title":"Observations of Aharonov-Bohm Conductance Oscillations in CVD-Grown Graphene Rings at 4K","authors":"Zitao Tang;Siwei Chen;Cynthia I. Osuala;Abdus Salam Sarkar;Grzegorz Hader;Aron Cummings;Stefan Strauf;Chunlei Qu;Eui-Hyeok Yang","doi":"10.1109/OJNANO.2023.3331974","DOIUrl":"10.1109/OJNANO.2023.3331974","url":null,"abstract":"We present the observations of Aharonov-Bohm (AB) oscillations in chemical vapor deposition (CVD)-grown graphene rings via magnetotransport measurements at 4K under out-of-plane external magnetic fields up to +/−2.1 T. Incorporating a baseline subtraction of the original conductance data allowed us to observe two-terminal conductance oscillations with a spacing of ΔB\u0000<sub>AB</sub>\u0000 of 3.66 to 32.9 mT from the ring with an inner radius of 200 nm and arm-width of 400 nm, and spacing of ΔB\u0000<sub>AB</sub>\u0000 from 2.1 mT to 8.2 mT from the ring with an inner radius of 400 nm and an arm-width of 400 nm. The fast-Fourier transform (FFT) data showed AB oscillation periods, with the interval of the \u0000<italic>h/e</i>\u0000 fundamental mode given by 30/T to 273/T for the ring with the inner radius of 200 nm and arm-width of 400 nm, and 122/T to 488/T for the ring with the inner radius of 400 nm. The broad spreading of FFT peaks is due to the aspect ratio of the inner radius \u0000<italic>r<sub>1</sub></i>\u0000 and the width \u0000<italic>w</i>\u0000 of the ring, \u0000<italic>r/w</i>\u0000 ∼ 1. Systematic numerical simulations were performed to elucidate the relation between the AB oscillation frequency and the geometry of the ring. This work shows AB oscillations in CVD-grown graphene rings at an elevated temperature (4K).","PeriodicalId":446,"journal":{"name":"IEEE Open Journal of Nanotechnology","volume":"4 ","pages":"208-214"},"PeriodicalIF":1.7,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10314768","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135604932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.1109/OJNANO.2023.3328425
Rajat Butola;Yiming Li;Sekhar Reddy Kola
Machine learning (ML) is poised to play an important part in advancing the predicting capability in semiconductor device compact modeling domain. One major advantage of ML-based compact modeling is its ability to capture complex relationships and patterns in large datasets. Therefore, in this paper a novel design scheme based on dynamically adaptive neural network (DANN) is proposed to develop fast and accurate compact model (CM). This framework constitutes a powerful yet computationally efficient methodology and exhibits emergent dynamic behaviors. This paper demonstrates that the compact model based on ML can be designed to replicate the performance of conventional compact model for nanodevices. For this work, gate-all-around (GAA) nanosheet (NS) device characteristics are comprehensively analyzed for process variability sources using the proposed model. The device geometry parameters such as channel length, nanosheet width and nanosheet thickness are fed as input features to the DANN model. The adaptive neural network learns dynamically by updating weights of the model in accordance with the input features and achieves accurate neural weight convergence. The proposed model predicted the electrical characteristics of NS devices with less than 1% error rate. The model is also implemented and validated for the simulations of digital circuit designs such as inverter, and logic gates.
{"title":"A Comprehensive Technique Based on Machine Learning for Device and Circuit Modeling of Gate-All-Around Nanosheet Transistors","authors":"Rajat Butola;Yiming Li;Sekhar Reddy Kola","doi":"10.1109/OJNANO.2023.3328425","DOIUrl":"10.1109/OJNANO.2023.3328425","url":null,"abstract":"Machine learning (ML) is poised to play an important part in advancing the predicting capability in semiconductor device compact modeling domain. One major advantage of ML-based compact modeling is its ability to capture complex relationships and patterns in large datasets. Therefore, in this paper a novel design scheme based on dynamically adaptive neural network (DANN) is proposed to develop fast and accurate compact model (CM). This framework constitutes a powerful yet computationally efficient methodology and exhibits emergent dynamic behaviors. This paper demonstrates that the compact model based on ML can be designed to replicate the performance of conventional compact model for nanodevices. For this work, gate-all-around (GAA) nanosheet (NS) device characteristics are comprehensively analyzed for process variability sources using the proposed model. The device geometry parameters such as channel length, nanosheet width and nanosheet thickness are fed as input features to the DANN model. The adaptive neural network learns dynamically by updating weights of the model in accordance with the input features and achieves accurate neural weight convergence. The proposed model predicted the electrical characteristics of NS devices with less than 1% error rate. The model is also implemented and validated for the simulations of digital circuit designs such as inverter, and logic gates.","PeriodicalId":446,"journal":{"name":"IEEE Open Journal of Nanotechnology","volume":"4 ","pages":"181-194"},"PeriodicalIF":1.7,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10301633","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135260945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-27DOI: 10.1109/OJNANO.2023.3327997
Tamiko Ohshima
Compared to solid target, powder target is low cost and can be varied in wide range of elemental combinations. Transparent and conductive aluminum-doped zinc oxide (AZO) thin films were prepared by sputter deposition using a mixed powder target consisting of zinc oxide and aluminum oxide powders at 98:2 wt%. The bulk density of the powder target can be varied depending on the pressing pressure. Therefore, AZO thin films were prepared on Si and sapphire substrates using powder targets with different bulk densities ( ρpowder ) ranging from 0.898 to 3.00 g/cm 3 . The fabricated structural, electrical, and optical properties of the AZO thin films were examined, and the relationships between the target bulk density and film properties were investigated. X-ray diffraction measurements revealed c-axis ZnO (002) diffraction peaks, corresponding to crystallite growth oriented perpendicular to the substrate. Hall effect measurements showed n-type conductivity, with carrier density and Hall mobility increasing as the bulk density of the powder target increased. At ρpowder = 3.00 g/cm 3 , the AZO thin film on the Si substrate showed the lowest resistivity of 1.35 × 10 −3 Ω·cm. UV-visible spectroscopy measurements showed that the average transmittance in the visible light region exceeded 80% for the AZO thin films on the sapphire substrates. The figure of merit was calculated as a measure of the potential application in optoelectronic devices, resulting in 6.37 × 10 −3 Ω −1 for ρpowder = 3.00 g/cm 3 . This research contributes to Nagasaki University's goal of “planetary health”.
{"title":"Sputtering Deposition With Low Cost Multi-Element Powder Targets","authors":"Tamiko Ohshima","doi":"10.1109/OJNANO.2023.3327997","DOIUrl":"10.1109/OJNANO.2023.3327997","url":null,"abstract":"Compared to solid target, powder target is low cost and can be varied in wide range of elemental combinations. Transparent and conductive aluminum-doped zinc oxide (AZO) thin films were prepared by sputter deposition using a mixed powder target consisting of zinc oxide and aluminum oxide powders at 98:2 wt%. The bulk density of the powder target can be varied depending on the pressing pressure. Therefore, AZO thin films were prepared on Si and sapphire substrates using powder targets with different bulk densities (\u0000<italic>ρ<sub>p</sub><sub>owder</sub></i>\u0000) ranging from 0.898 to 3.00 g/cm\u0000<sup>3</sup>\u0000. The fabricated structural, electrical, and optical properties of the AZO thin films were examined, and the relationships between the target bulk density and film properties were investigated. X-ray diffraction measurements revealed c-axis ZnO (002) diffraction peaks, corresponding to crystallite growth oriented perpendicular to the substrate. Hall effect measurements showed n-type conductivity, with carrier density and Hall mobility increasing as the bulk density of the powder target increased. At \u0000<italic>ρ<sub>p</sub><sub>owder</sub></i>\u0000 = 3.00 g/cm\u0000<sup>3</sup>\u0000, the AZO thin film on the Si substrate showed the lowest resistivity of 1.35 × 10\u0000<sup>−3</sup>\u0000 Ω·cm. UV-visible spectroscopy measurements showed that the average transmittance in the visible light region exceeded 80% for the AZO thin films on the sapphire substrates. The figure of merit was calculated as a measure of the potential application in optoelectronic devices, resulting in 6.37 × 10\u0000<sup>−3</sup>\u0000 Ω\u0000<sup>−1</sup>\u0000 for \u0000<italic>ρ<sub>p</sub><sub>owder</sub></i>\u0000 = 3.00 g/cm\u0000<sup>3</sup>\u0000. This research contributes to Nagasaki University's goal of “planetary health”.","PeriodicalId":446,"journal":{"name":"IEEE Open Journal of Nanotechnology","volume":"4 ","pages":"172-180"},"PeriodicalIF":1.7,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10298617","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135212984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article describes the fabrication and experimental results of a novel step structure Radio Frequency Microelectromechanical system (RF MEMS) switch integrated with a circular patch antenna. The RF MEMS switch is developed using surface micromachining technology and exhibits several desirable characteristics. The key findings and features of the proposed RF MEMS switch are as follows: The switch operates at a very low pull-in voltage of 4.4 V, which is advantageous as it requires low actuation voltage for switching operations. Low ON State Capacitance: The switch demonstrates a low ON state capacitance of 81.2 fF, indicating efficient switching performance. High Isolation: The switch exhibits high isolation of −60.68 dB at 23 GHz, which is the central frequency of the K-band. This high isolation ensures minimal interference and improved signal integrity. The RF MEMS switch is integrated with a circular patch antenna, enabling reconfigurability in the operating frequency of the antenna. The antenna's frequency can be adjusted by actuating the switches alternatively. The specific operating frequencies and return loss values are as follows: Both Switches ON: The antenna radiates the signal at a frequency of 19.2 GHz with a return loss of −26.7 dB. Only Switch A ON: The antenna radiates at a frequency of 21 GHz with a return loss of −17.6 dB. Only Switch B ON: The antenna radiates the signal at a frequency of 26.4 GHz with a return loss of −17.47 dB. The RF MEMS switch and antenna are optimized to transmit RF signals within the K-band frequency range. The integration of the step structured RF MEMS switches successfully enables reconfiguration of the antenna's operating frequency. The proposed antenna, integrated with the RF MEMS switches, has potential applications in various K-band systems, including surface movement radars, direct broadcast satellite, Direct-to-Home (DHT) television, and 5th Generation (5G) mobile communication. The reconfigurability of the antenna's frequency allows for flexibility and adaptability in different K-band applications.
{"title":"Design, Fabrication and Measurement of Radio Frequency Micro-Electro-Mechanical Systems","authors":"Girija Sravani Kondavitee;Young Suh Song;Srinivasa Rao Karumuri;Koushik Guha;Brajesh Kumar Kaushik;Aimé Lay-Ekuakille","doi":"10.1109/OJNANO.2023.3318236","DOIUrl":"10.1109/OJNANO.2023.3318236","url":null,"abstract":"This article describes the fabrication and experimental results of a novel step structure Radio Frequency Microelectromechanical system (RF MEMS) switch integrated with a circular patch antenna. The RF MEMS switch is developed using surface micromachining technology and exhibits several desirable characteristics. The key findings and features of the proposed RF MEMS switch are as follows: The switch operates at a very low pull-in voltage of 4.4 V, which is advantageous as it requires low actuation voltage for switching operations. Low ON State Capacitance: The switch demonstrates a low ON state capacitance of 81.2 fF, indicating efficient switching performance. High Isolation: The switch exhibits high isolation of −60.68 dB at 23 GHz, which is the central frequency of the K-band. This high isolation ensures minimal interference and improved signal integrity. The RF MEMS switch is integrated with a circular patch antenna, enabling reconfigurability in the operating frequency of the antenna. The antenna's frequency can be adjusted by actuating the switches alternatively. The specific operating frequencies and return loss values are as follows: Both Switches ON: The antenna radiates the signal at a frequency of 19.2 GHz with a return loss of −26.7 dB. Only Switch A ON: The antenna radiates at a frequency of 21 GHz with a return loss of −17.6 dB. Only Switch B ON: The antenna radiates the signal at a frequency of 26.4 GHz with a return loss of −17.47 dB. The RF MEMS switch and antenna are optimized to transmit RF signals within the K-band frequency range. The integration of the step structured RF MEMS switches successfully enables reconfiguration of the antenna's operating frequency. The proposed antenna, integrated with the RF MEMS switches, has potential applications in various K-band systems, including surface movement radars, direct broadcast satellite, Direct-to-Home (DHT) television, and 5th Generation (5G) mobile communication. The reconfigurability of the antenna's frequency allows for flexibility and adaptability in different K-band applications.","PeriodicalId":446,"journal":{"name":"IEEE Open Journal of Nanotechnology","volume":"4 ","pages":"195-207"},"PeriodicalIF":1.7,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10269333","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135913448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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