This letter proposes a method to monitor the dynamic extension process of the depletion region in GaN HEMTs. Based on a channel-probe branch structure, the transient channel potential ( $text {V}_{text {CP}}$ ) at a certain distance from the gate was measured under off-state conditions. From the transient $text {V}_{text {CP}}$ curves, the extension time of the depletion region was directly obtained for the first time, and it was found to exhibit an exponential dependence on the drain-gate bias ( $text {V}_{text {DG}}$ ) under off-state conditions. Comparison study of devices with and without $text {SiN}_{text {x}}$ passivation reveals the dominant role of surface traps in the extension process. The equivalent surface charging current is derived from the extension time of the depletion region, with which the dominated surface charge transport mechanism is revealed to be Poole-Frenkel emission.
{"title":"Dynamic Extension Behavior of the Depletion Region in GaN HEMTs Monitored With a Channel-Probe Branch Structure","authors":"Xin Wang;Jinyan Wang;Bin Zhang;Chen Wang;Ziheng Liu;Jiayin He;Ju Gao;Hongyue Wang;Jin Wei;Maojun Wang","doi":"10.1109/LED.2024.3485639","DOIUrl":"https://doi.org/10.1109/LED.2024.3485639","url":null,"abstract":"This letter proposes a method to monitor the dynamic extension process of the depletion region in GaN HEMTs. Based on a channel-probe branch structure, the transient channel potential (\u0000<inline-formula> <tex-math>$text {V}_{text {CP}}$ </tex-math></inline-formula>\u0000) at a certain distance from the gate was measured under off-state conditions. From the transient \u0000<inline-formula> <tex-math>$text {V}_{text {CP}}$ </tex-math></inline-formula>\u0000 curves, the extension time of the depletion region was directly obtained for the first time, and it was found to exhibit an exponential dependence on the drain-gate bias (\u0000<inline-formula> <tex-math>$text {V}_{text {DG}}$ </tex-math></inline-formula>\u0000) under off-state conditions. Comparison study of devices with and without \u0000<inline-formula> <tex-math>$text {SiN}_{text {x}}$ </tex-math></inline-formula>\u0000 passivation reveals the dominant role of surface traps in the extension process. The equivalent surface charging current is derived from the extension time of the depletion region, with which the dominated surface charge transport mechanism is revealed to be Poole-Frenkel emission.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"45 12","pages":"2295-2298"},"PeriodicalIF":4.1,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1109/LED.2024.3485631
Zewei Dong;Yun Bai;Leshan Qiu;Chengyue Yang;Jilong Hao;Yidan Tang;Xuan Li;Xiaoli Tian;Xinyu Liu
This letter reports the bias temperature instabilities (BTI) of 4H-SiC CMOS devices with different gate lengths (L) and gate widths (W) for integrated circuits at 400 °C for the first time. The result shows that the threshold voltage shift of p-channel MOSFETs is significantly higher than that of n-channel MOSFETs. More serious BTI degradation is observed in CMOS devices with shorter L, especially for p-channel MOSFETs. Additionally, higher gate leakage current density and charged interface traps density are also found in fresh devices with shorter L. Through the energy-band structure, the physical cause of difference in transistor sizes originates from the inhomogeneous channel carrier concentration and charged interface traps density caused by the source and drain diffusion regions.
{"title":"Gate Length Dependence of Bias Temperature Instabilities up to 400 °C in 4H-SiC CMOS Devices","authors":"Zewei Dong;Yun Bai;Leshan Qiu;Chengyue Yang;Jilong Hao;Yidan Tang;Xuan Li;Xiaoli Tian;Xinyu Liu","doi":"10.1109/LED.2024.3485631","DOIUrl":"https://doi.org/10.1109/LED.2024.3485631","url":null,"abstract":"This letter reports the bias temperature instabilities (BTI) of 4H-SiC CMOS devices with different gate lengths (L) and gate widths (W) for integrated circuits at 400 °C for the first time. The result shows that the threshold voltage shift of p-channel MOSFETs is significantly higher than that of n-channel MOSFETs. More serious BTI degradation is observed in CMOS devices with shorter L, especially for p-channel MOSFETs. Additionally, higher gate leakage current density and charged interface traps density are also found in fresh devices with shorter L. Through the energy-band structure, the physical cause of difference in transistor sizes originates from the inhomogeneous channel carrier concentration and charged interface traps density caused by the source and drain diffusion regions.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"45 12","pages":"2319-2322"},"PeriodicalIF":4.1,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1109/LED.2024.3485683
Wen Zhao;Satoshi Koizumi;Meiyong Liao
P-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) have been demonstrated on phosphorus-doped n-type diamond epilayers. The p-channel nature arises from the surface conductivity resulting from hydrogenated termination on the n-type diamond surface. The MOSFET exhibits normally-on properties and shows a threshold of 1.8 V for the phosphorus concentration of 1016 cm−3 and an on/off ratio of 107. The maximum drain current is approximately −4.5 mA/mm and the transconductance is 0.75 mS/mm, which decreases as the phosphorus concentration in the n-type diamond epilayer increases. The demonstration of p-channel MOSFETs on n-type diamond epilayers paves the way for the development of complementary MOS (CMOS) circuits on a single diamond wafer.
{"title":"P-Channel MOSFETs on Phosphorous-Doped n-Type Diamond","authors":"Wen Zhao;Satoshi Koizumi;Meiyong Liao","doi":"10.1109/LED.2024.3485683","DOIUrl":"https://doi.org/10.1109/LED.2024.3485683","url":null,"abstract":"P-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) have been demonstrated on phosphorus-doped n-type diamond epilayers. The p-channel nature arises from the surface conductivity resulting from hydrogenated termination on the n-type diamond surface. The MOSFET exhibits normally-on properties and shows a threshold of 1.8 V for the phosphorus concentration of 1016 cm−3 and an on/off ratio of 107. The maximum drain current is approximately −4.5 mA/mm and the transconductance is 0.75 mS/mm, which decreases as the phosphorus concentration in the n-type diamond epilayer increases. The demonstration of p-channel MOSFETs on n-type diamond epilayers paves the way for the development of complementary MOS (CMOS) circuits on a single diamond wafer.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"45 12","pages":"2268-2271"},"PeriodicalIF":4.1,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multi-level cell (MLC) ferroelectric FETs (FeFETs) face critical reliability challenges including variation, endurance and write disturb. In this work, we proposed an innovative solution to tackle all the three challenges within a compact writing scheme. Combining error correction, endurance recovery, and self-compensated writing, the proposed scheme achieves a $gt 6times $ reduction in error ratio (ER), a >100 improvement in endurance, and a $gt 7times $ reduction in Vth shift. Reliable 2 bits/cell storage with high endurance of $10^{{8}}$ cycles and write-disturb immunity is experimentally demonstrated in the fabricated 1T FeFET array. This writing scheme is realized within a single work flow, and can be readily implemented in the operation circuits.
{"title":"A Compact Writing Scheme for the Reliability Challenges in 1T Multi-Level FeFET Array: Variation, Endurance, and Write Disturb","authors":"Yuejia Zhou;Hanyong Shao;Weiqin Huang;Runteng Zhu;Yihan Zhang;Ru Huang;Kechao Tang","doi":"10.1109/LED.2024.3485803","DOIUrl":"https://doi.org/10.1109/LED.2024.3485803","url":null,"abstract":"Multi-level cell (MLC) ferroelectric FETs (FeFETs) face critical reliability challenges including variation, endurance and write disturb. In this work, we proposed an innovative solution to tackle all the three challenges within a compact writing scheme. Combining error correction, endurance recovery, and self-compensated writing, the proposed scheme achieves a \u0000<inline-formula> <tex-math>$gt 6times $ </tex-math></inline-formula>\u0000 reduction in error ratio (ER), a >100 improvement in endurance, and a \u0000<inline-formula> <tex-math>$gt 7times $ </tex-math></inline-formula>\u0000 reduction in Vth shift. Reliable 2 bits/cell storage with high endurance of \u0000<inline-formula> <tex-math>$10^{{8}}$ </tex-math></inline-formula>\u0000 cycles and write-disturb immunity is experimentally demonstrated in the fabricated 1T FeFET array. This writing scheme is realized within a single work flow, and can be readily implemented in the operation circuits.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"45 12","pages":"2387-2390"},"PeriodicalIF":4.1,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142736477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1109/LED.2024.3485905
Tianyu Xie;Wei Li;Yuqi Wang;Ruixin Song;Yue Wang;Wen Xu;Donglei Zhou;Hongwei Song
Currently, silicon solar cells (SSCs) have been the most widely used photovoltaic devices all around the world. However, the fundamental studies about SSCs are moving slowly as one of the key obstacles is the limited response to ultraviolet (UV) light. Here, we use the Yb $^{{3}+}$ doped perovskite quantum dots (PeQDs) with highly efficient quantum cutting emission to enhance the UV response of SSCs. Zn $^{{2}+}$ ions are co-doped to increase the exciton binding energy, decrease the defect density and improve the tolerance factor of PeQDs. Experimental and theoretical results show that Zn $^{{2}+}$ , Yb $^{{3}+}$ co-doped CsPbCl3 PeQDs are successfully synthesized with a photoluminescence quantum yield (PLQY) of 182.4%. By integrating PeQDs film with SSCs, the spectral response in the range of $200sim 400$ nm is largely enhanced. Importantly, the maximum photovoltaic conversion efficiency (PCE) of SSCs is increased from 18.6% to 21.2%. This study proposes a more cost-effective, convenient, and effective method for improving the PCE of SSCs, which is in line with the current industry’s application requirements and urgent problems to be solved.
{"title":"Quantum Cutting Photovoltaic Conversion Film Doped With Zinc and Ytterbium for Silicon Solar Cells","authors":"Tianyu Xie;Wei Li;Yuqi Wang;Ruixin Song;Yue Wang;Wen Xu;Donglei Zhou;Hongwei Song","doi":"10.1109/LED.2024.3485905","DOIUrl":"https://doi.org/10.1109/LED.2024.3485905","url":null,"abstract":"Currently, silicon solar cells (SSCs) have been the most widely used photovoltaic devices all around the world. However, the fundamental studies about SSCs are moving slowly as one of the key obstacles is the limited response to ultraviolet (UV) light. Here, we use the Yb\u0000<inline-formula> <tex-math>$^{{3}+}$ </tex-math></inline-formula>\u0000 doped perovskite quantum dots (PeQDs) with highly efficient quantum cutting emission to enhance the UV response of SSCs. Zn\u0000<inline-formula> <tex-math>$^{{2}+}$ </tex-math></inline-formula>\u0000 ions are co-doped to increase the exciton binding energy, decrease the defect density and improve the tolerance factor of PeQDs. Experimental and theoretical results show that Zn\u0000<inline-formula> <tex-math>$^{{2}+}$ </tex-math></inline-formula>\u0000, Yb\u0000<inline-formula> <tex-math>$^{{3}+}$ </tex-math></inline-formula>\u0000 co-doped CsPbCl3 PeQDs are successfully synthesized with a photoluminescence quantum yield (PLQY) of 182.4%. By integrating PeQDs film with SSCs, the spectral response in the range of \u0000<inline-formula> <tex-math>$200sim 400$ </tex-math></inline-formula>\u0000 nm is largely enhanced. Importantly, the maximum photovoltaic conversion efficiency (PCE) of SSCs is increased from 18.6% to 21.2%. This study proposes a more cost-effective, convenient, and effective method for improving the PCE of SSCs, which is in line with the current industry’s application requirements and urgent problems to be solved.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"45 12","pages":"2471-2474"},"PeriodicalIF":4.1,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, we employ GIXRD to determine that the HfO2/ZrO2 superlattice (SL-HZO) exhibits a higher proportion of orthorhombic phase than conventional HZO. We first demonstrate low-temperature polycrystalline silicon (LTPS) formed by green laser crystallization with SL-HZO to manufacture ferroelectric FinFET (Fe-FinFET). SEM and AFM analyses confirmed the high quality of the modified polycrystalline silicon channel. The LTPS/SL-HZO Fe-FinFET demonstrated an impressive memory window (MW) of 1.93 V under ±5 V high-speed (100 ns) pulse operation. It exhibited a robust endurance of $10^{{6}}$ cycles, with the MW remaining stable at 1.92 V over $10^{{4}}$ s without degradation. In conclusion, the LTPS/SL-HZO Fe-FinFET shows outstanding performance and reliability, indicating significant potential for non-volatile memory applications.
{"title":"High-Reliability HfO2/ZrO2 Superlattice Ferroelectric Poly-Si FinFET Memory Device Utilizing Green Laser Crystallization","authors":"Chen-You Wei;Yung-Teng Fang;Yi-Ju Yao;Chih-Chao Yang;Fu-Ju Hou;Chien-Chun Chen;Yung-Hsien Wu;Yung-Chun Wu","doi":"10.1109/LED.2024.3485900","DOIUrl":"https://doi.org/10.1109/LED.2024.3485900","url":null,"abstract":"In this study, we employ GIXRD to determine that the HfO2/ZrO2 superlattice (SL-HZO) exhibits a higher proportion of orthorhombic phase than conventional HZO. We first demonstrate low-temperature polycrystalline silicon (LTPS) formed by green laser crystallization with SL-HZO to manufacture ferroelectric FinFET (Fe-FinFET). SEM and AFM analyses confirmed the high quality of the modified polycrystalline silicon channel. The LTPS/SL-HZO Fe-FinFET demonstrated an impressive memory window (MW) of 1.93 V under ±5 V high-speed (100 ns) pulse operation. It exhibited a robust endurance of \u0000<inline-formula> <tex-math>$10^{{6}}$ </tex-math></inline-formula>\u0000 cycles, with the MW remaining stable at 1.92 V over \u0000<inline-formula> <tex-math>$10^{{4}}$ </tex-math></inline-formula>\u0000 s without degradation. In conclusion, the LTPS/SL-HZO Fe-FinFET shows outstanding performance and reliability, indicating significant potential for non-volatile memory applications.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"45 12","pages":"2272-2275"},"PeriodicalIF":4.1,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-23DOI: 10.1109/LED.2024.3485077
Shuning Zhang;Fansen Cao;Haoyu Lu;Yingfen Wei;Xuanyu Zhao;Hao Jiang;Xiaobing Yan;Qi Liu
In this study, we explore the transparent hafnia-based ferroelectric capacitors (FeCaps), employing transparent indium tin oxide (ITO) as the electrode and quartz as substrate. Through interface engineering, involving a Ti interlayer between the ferroelectric Hf $_{{0}.{5}}$ Zr $_{{0}.{5}}$ O2 (HZO) film and the electrodes, we not only achieve a substantial enhancement in polarization, but also manage to process within a reduced thermal budget ( $350~^{text {o}}$ C) compatible with back end of line (BEOL). The bottom interface is demonstrated to play the major role in improving the ferroelectric properties. Moreover, the transparent FeCaps exhibit a maximum transmittance of about 90% close to the bare substrate under visible light. These findings pave the way for hafnia-based FeCaps in the future advancement of transparent electronics.
{"title":"Interface Engineering on Ferroelectricity of Transparent Hf₀.₅Zr₀.₅O₂ Ferroelectric Capacitors","authors":"Shuning Zhang;Fansen Cao;Haoyu Lu;Yingfen Wei;Xuanyu Zhao;Hao Jiang;Xiaobing Yan;Qi Liu","doi":"10.1109/LED.2024.3485077","DOIUrl":"https://doi.org/10.1109/LED.2024.3485077","url":null,"abstract":"In this study, we explore the transparent hafnia-based ferroelectric capacitors (FeCaps), employing transparent indium tin oxide (ITO) as the electrode and quartz as substrate. Through interface engineering, involving a Ti interlayer between the ferroelectric Hf\u0000<inline-formula> <tex-math>$_{{0}.{5}}$ </tex-math></inline-formula>\u0000Zr\u0000<inline-formula> <tex-math>$_{{0}.{5}}$ </tex-math></inline-formula>\u0000O2 (HZO) film and the electrodes, we not only achieve a substantial enhancement in polarization, but also manage to process within a reduced thermal budget (\u0000<inline-formula> <tex-math>$350~^{text {o}}$ </tex-math></inline-formula>\u0000C) compatible with back end of line (BEOL). The bottom interface is demonstrated to play the major role in improving the ferroelectric properties. Moreover, the transparent FeCaps exhibit a maximum transmittance of about 90% close to the bare substrate under visible light. These findings pave the way for hafnia-based FeCaps in the future advancement of transparent electronics.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"45 12","pages":"2347-2350"},"PeriodicalIF":4.1,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142736315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Acoustically actuated microrobots have attracted considerable attention, which have developed various geometries. These microrobots are powered through their interaction with acoustics. The use of ultrahigh-frequency (UHF) ultrasound yields a focus on the order of several microns, thus actuating microrobots with accurate, strong, and two-directional forces. However, to date no technique can simultaneously calibrate the actual axial and lateral radiation forces of UHF ultrasound above 60 MHz acting on a microrobot with arbitrary geometry. To address this issue, we present a force sensor based on a micropipette. The force sensor consists of the micropipette, microrobot with a marker, and fixed base, which calibrates the overall spring constants. By combining the two-directional displacements actuated by the axial and lateral radiation forces, we calibrated the forces with a resolution of hundreds of piconewtons. We calibrated the axial and lateral radiation forces on cylindrical and spherical microrobots with the same volume and further investigated the influences of the duty factor and excitation voltage. This method complements a crucial design link in UHF ultrasound actuating microrobots.
{"title":"Simultaneous Calibration of Axial and Lateral Radiation Forces of Ultra-High Frequency Ultrasound Acting on a Microrobot With Arbitrary Geometry","authors":"Jinzhe Wu;Jialin Shi;Zhaoxi Li;Peng Yu;Huiyao Shi;Si Tang;Shanshan Chen;Chunlong Fei;Chanmin Su;Lianqing Liu","doi":"10.1109/LED.2024.3483907","DOIUrl":"https://doi.org/10.1109/LED.2024.3483907","url":null,"abstract":"Acoustically actuated microrobots have attracted considerable attention, which have developed various geometries. These microrobots are powered through their interaction with acoustics. The use of ultrahigh-frequency (UHF) ultrasound yields a focus on the order of several microns, thus actuating microrobots with accurate, strong, and two-directional forces. However, to date no technique can simultaneously calibrate the actual axial and lateral radiation forces of UHF ultrasound above 60 MHz acting on a microrobot with arbitrary geometry. To address this issue, we present a force sensor based on a micropipette. The force sensor consists of the micropipette, microrobot with a marker, and fixed base, which calibrates the overall spring constants. By combining the two-directional displacements actuated by the axial and lateral radiation forces, we calibrated the forces with a resolution of hundreds of piconewtons. We calibrated the axial and lateral radiation forces on cylindrical and spherical microrobots with the same volume and further investigated the influences of the duty factor and excitation voltage. This method complements a crucial design link in UHF ultrasound actuating microrobots.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"45 12","pages":"2534-2537"},"PeriodicalIF":4.1,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-21DOI: 10.1109/LED.2024.3484218
S. Ponomarenko;H. P. Laqua;K. A. Avramidis;G. Gantenbein;J. Gontard;F. Hollmann;S. Illy;Z. C. Ioannidis;J. Jelonnek;J. Jin;S. Kohler;L. Krier;A. Leggieri;F. Legrand;G. Lietaer;C. Lievin;S. Marsen;D. Moseev;F. Noke;T. Rzesnicki;T. Stange;M. Thumm;R. C. Wolf
In this work, we present the achievements obtained during the commissioning phase of the newly developed 140-GHz continuous-wave tube TH1507U at the gyrotron test stand of the electron-cyclotron resonance heating facility of the Wendelstein 7-X stellarator. The gyrotron is based on the successful 1-MW class industrial TH1507 gyrotron, which operates in the TE $_{{28},{8}}$ mode, and has been optimized for operation in the higher-order TE $_{{28},{10}}$ mode. The 1-ms short-pulse tests confirmed the nominal output power of 1.5 MW. In a long-pulse operating regime, an output power of 1.3 MW with total efficiency 45.9% was demonstrated at pulse lengths of 3 minutes. Different regimes where the beam current is above 50 A demonstrated a saturation of output power at 1.3 MW, that can be explained by the presence of parasitic modes. A parasite-free operation with an output power of 1.2 MW was achieved with pulses up to 580 s in length. The pulse length was limited due to the existing capabilities of the cooling system at the test stand, and is foreseen to be extended in the future.
{"title":"Experimental Results of the Novel 1.5-MW-Class 140-GHz Continuous-Wave Gyrotron for the Wendelstein 7-X Stellarator","authors":"S. Ponomarenko;H. P. Laqua;K. A. Avramidis;G. Gantenbein;J. Gontard;F. Hollmann;S. Illy;Z. C. Ioannidis;J. Jelonnek;J. Jin;S. Kohler;L. Krier;A. Leggieri;F. Legrand;G. Lietaer;C. Lievin;S. Marsen;D. Moseev;F. Noke;T. Rzesnicki;T. Stange;M. Thumm;R. C. Wolf","doi":"10.1109/LED.2024.3484218","DOIUrl":"https://doi.org/10.1109/LED.2024.3484218","url":null,"abstract":"In this work, we present the achievements obtained during the commissioning phase of the newly developed 140-GHz continuous-wave tube TH1507U at the gyrotron test stand of the electron-cyclotron resonance heating facility of the Wendelstein 7-X stellarator. The gyrotron is based on the successful 1-MW class industrial TH1507 gyrotron, which operates in the TE\u0000<inline-formula> <tex-math>$_{{28},{8}}$ </tex-math></inline-formula>\u0000 mode, and has been optimized for operation in the higher-order TE\u0000<inline-formula> <tex-math>$_{{28},{10}}$ </tex-math></inline-formula>\u0000 mode. The 1-ms short-pulse tests confirmed the nominal output power of 1.5 MW. In a long-pulse operating regime, an output power of 1.3 MW with total efficiency 45.9% was demonstrated at pulse lengths of 3 minutes. Different regimes where the beam current is above 50 A demonstrated a saturation of output power at 1.3 MW, that can be explained by the presence of parasitic modes. A parasite-free operation with an output power of 1.2 MW was achieved with pulses up to 580 s in length. The pulse length was limited due to the existing capabilities of the cooling system at the test stand, and is foreseen to be extended in the future.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"45 12","pages":"2550-2553"},"PeriodicalIF":4.1,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10723780","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-21DOI: 10.1109/LED.2024.3483972
Zhong-Wei Lin;Sheng-Shian Li
The challenges of operating Micro-Electro-Mechanical Systems (MEMS) resonators in conductive liquid medium were addressed in this study, which is crucial for applications in biomedical sensing, chemical analysis, and environmental monitoring. High ionic conductivity has been encountered by traditional approaches, leading to substantial feedthrough interference that conceals resonant signals. We introduce a novel shielded signal pad/interconnect configuration to overcome these limitations. By driving/sensing the resonator through the shielded pad/interconnect and grounding the exposed ones, feedthrough effects were reduced, and resonance readability was enhanced across a much broader frequency spectrum compared to previous method. Improved performance of AlN-based MEMS resonators in liquid medium was demonstrated through experimental results, with phase noise performance in ionic environments of −22.17 dBc/Hz at 10 Hz offset and −99.45 dBc/Hz at 10 kHz offset. A mass resolution of 3.3 pg in ionic liquids is achieved by the resonator/oscillator, proving its applicability for real-time sensing. These findings offer a robust solution for maintaining MEMS resonator/oscillator functionality in conductive liquid and pave the way for future advancements.
{"title":"A Generic Signal Shielding Technique for MEMS Resonators in Conductive Liquid","authors":"Zhong-Wei Lin;Sheng-Shian Li","doi":"10.1109/LED.2024.3483972","DOIUrl":"https://doi.org/10.1109/LED.2024.3483972","url":null,"abstract":"The challenges of operating Micro-Electro-Mechanical Systems (MEMS) resonators in conductive liquid medium were addressed in this study, which is crucial for applications in biomedical sensing, chemical analysis, and environmental monitoring. High ionic conductivity has been encountered by traditional approaches, leading to substantial feedthrough interference that conceals resonant signals. We introduce a novel shielded signal pad/interconnect configuration to overcome these limitations. By driving/sensing the resonator through the shielded pad/interconnect and grounding the exposed ones, feedthrough effects were reduced, and resonance readability was enhanced across a much broader frequency spectrum compared to previous method. Improved performance of AlN-based MEMS resonators in liquid medium was demonstrated through experimental results, with phase noise performance in ionic environments of −22.17 dBc/Hz at 10 Hz offset and −99.45 dBc/Hz at 10 kHz offset. A mass resolution of 3.3 pg in ionic liquids is achieved by the resonator/oscillator, proving its applicability for real-time sensing. These findings offer a robust solution for maintaining MEMS resonator/oscillator functionality in conductive liquid and pave the way for future advancements.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"45 12","pages":"2538-2541"},"PeriodicalIF":4.1,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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