ELF （extremely low frequency） magnetic fields from power-line current influence the yield of CMOS foundry. The poor yield happens because of ELF magnetic fields inducing directly the measurement or process equipment...ELF （extremely low frequency） magnetic fields from power-line current influence the yield of CMOS foundry. The poor yield happens because of ELF magnetic fields inducing directly the measurement or process equipment for cutting-edge chips below 28 nm process. The equipments of electron microscopes, including SEM （scanning electron microscope）, TEM （transmission electron microscopy）, STEM （scanning transmission electron microscopy） and EBLS （electron beam lithography system） are very susceptible to ELF magnetic fields emanating from various electrical power sources outside of the building and within next generation CMOS foundry recommends a maximum of 0.3 mG. The active canceling method uses active coils with current sensing field via sensor and inducing man-made electromagnetic field to reduce the stray magnetic field. Unfortunately, the conventional system takes more time to products field because of parasitical capacitance and resistance in long coil. The longer canceling coil the system construct, the more time it takes. Besides, canceling system should spend more time on calibrating non-linear current amplifier through software design. This research designs simpler anti-electro-magnetic system instead of typical frame and develops one turn canceling coil structure to reduce delaying time. Several parallel cells generate field up to 23.81 mG controlled by MPU （micro processor unit）. This system decreases the power-line inducing filed below 0.3 mG.展开更多
In this study, the magnetic field was lessened by mirror array power cable system, and simulation of results predicted the best permutations to decrease electromagnetic influence （EMI） value below 0.4 mG at working ...In this study, the magnetic field was lessened by mirror array power cable system, and simulation of results predicted the best permutations to decrease electromagnetic influence （EMI） value below 0.4 mG at working space without any shielding. Furthermore, this innovative method will cost down at high technology nano-Fab especially for 28 nanometer process. Through the theoretical study and numerical simulation, we predict the best permutation for mitigating EMI noise from three-phase electric power lines system without any shielding system down to 1.2 mG in 3.0 m distance from applying I = 50 A at 60 Hz with 12 series cable tray system. Followed above discussions, this study indicated different and new perspectives with before opinions of some researcher. The measured magnetic field values on the nano-Fab are in good agreement with this simulation results. These good results give more confident to apply in new building nano-Fab system. Furthermore, this innovation will cost down for EMI shielding at high technology nano-Fab especially for 40 （and below） nanometer process.展开更多
A semiconductor/dielectric interface is one of the dominant factors in device characteristics,and a variety of oxides with high dielectric constants and low interface trap densities have been used in carbon nanotube t...A semiconductor/dielectric interface is one of the dominant factors in device characteristics,and a variety of oxides with high dielectric constants and low interface trap densities have been used in carbon nanotube transistors.Given the crystal structure of nanotubes with no dangling bonds,there remains room to investigate unconventional dielectric materials.Here,we fabricate carbon nanotube transistors with boron nitride nanotubes as interfacial layers between channels and gate dielectrics,where a single semiconducting nanotube is used to focus on switching behaviors at the subthreshold regime.The subthreshold swing of 68 mV·dec^(−1)is obtained despite a 100-nm-thick Sio_(2)dielectric,corresponding to the effective interface trap density of 5.2×10^(11)cm^(−2)·eV^(−1),one order of magnitude lower than those of carbon nanotube devices without boron nitride passivation.The interfacial layers also result in the mild suppression of threshold voltage variation and hysteresis.We achieve Ohmic contacts through the selective etching of boron nitride nanotubes with XeF2 gas,overcoming the trade-off imposed by wrapping the inner nanotubes.Negligible impacts of fluorinating carbon nanotubes on device performances are also confirmed as long as the etching is applied exclusively at source/drain regions.Our results represent an important step toward nanoelectronics that exploit the advantage of one-dimensional van der Waals heterostructures.展开更多
文摘ELF （extremely low frequency） magnetic fields from power-line current influence the yield of CMOS foundry. The poor yield happens because of ELF magnetic fields inducing directly the measurement or process equipment for cutting-edge chips below 28 nm process. The equipments of electron microscopes, including SEM （scanning electron microscope）, TEM （transmission electron microscopy）, STEM （scanning transmission electron microscopy） and EBLS （electron beam lithography system） are very susceptible to ELF magnetic fields emanating from various electrical power sources outside of the building and within next generation CMOS foundry recommends a maximum of 0.3 mG. The active canceling method uses active coils with current sensing field via sensor and inducing man-made electromagnetic field to reduce the stray magnetic field. Unfortunately, the conventional system takes more time to products field because of parasitical capacitance and resistance in long coil. The longer canceling coil the system construct, the more time it takes. Besides, canceling system should spend more time on calibrating non-linear current amplifier through software design. This research designs simpler anti-electro-magnetic system instead of typical frame and develops one turn canceling coil structure to reduce delaying time. Several parallel cells generate field up to 23.81 mG controlled by MPU （micro processor unit）. This system decreases the power-line inducing filed below 0.3 mG.
文摘In this study, the magnetic field was lessened by mirror array power cable system, and simulation of results predicted the best permutations to decrease electromagnetic influence （EMI） value below 0.4 mG at working space without any shielding. Furthermore, this innovative method will cost down at high technology nano-Fab especially for 28 nanometer process. Through the theoretical study and numerical simulation, we predict the best permutation for mitigating EMI noise from three-phase electric power lines system without any shielding system down to 1.2 mG in 3.0 m distance from applying I = 50 A at 60 Hz with 12 series cable tray system. Followed above discussions, this study indicated different and new perspectives with before opinions of some researcher. The measured magnetic field values on the nano-Fab are in good agreement with this simulation results. These good results give more confident to apply in new building nano-Fab system. Furthermore, this innovation will cost down for EMI shielding at high technology nano-Fab especially for 40 （and below） nanometer process.
基金supported by JSPS(Nos.KAKENHI JP22H01411,JP20H00220,JP23H05443,JP21H05233,and JP23H02052),JST(No.CREST JPMJCR20B5)World Premier International Research Center Initiative(WPI)and the Ministry of Education,Culture,Sports,Science and Technology(MEXT),Japan.A part of this work was conducted at Takeda Sentanchi Supercleanroom,The University of Tokyo,supported by“Advanced Research Infrastructure for Materials and Nanotechnology in Japan(ARIM)”of MEXT(Proposal Number JPMXP09F22UT1086).
文摘A semiconductor/dielectric interface is one of the dominant factors in device characteristics,and a variety of oxides with high dielectric constants and low interface trap densities have been used in carbon nanotube transistors.Given the crystal structure of nanotubes with no dangling bonds,there remains room to investigate unconventional dielectric materials.Here,we fabricate carbon nanotube transistors with boron nitride nanotubes as interfacial layers between channels and gate dielectrics,where a single semiconducting nanotube is used to focus on switching behaviors at the subthreshold regime.The subthreshold swing of 68 mV·dec^(−1)is obtained despite a 100-nm-thick Sio_(2)dielectric,corresponding to the effective interface trap density of 5.2×10^(11)cm^(−2)·eV^(−1),one order of magnitude lower than those of carbon nanotube devices without boron nitride passivation.The interfacial layers also result in the mild suppression of threshold voltage variation and hysteresis.We achieve Ohmic contacts through the selective etching of boron nitride nanotubes with XeF2 gas,overcoming the trade-off imposed by wrapping the inner nanotubes.Negligible impacts of fluorinating carbon nanotubes on device performances are also confirmed as long as the etching is applied exclusively at source/drain regions.Our results represent an important step toward nanoelectronics that exploit the advantage of one-dimensional van der Waals heterostructures.
