We present an all-e-beam lithography （EBL） process for the patterning of photonic crystal waveguides. The whole device structures are exposed in two steps. Holes constituting the photonic crystal lattice and defects...We present an all-e-beam lithography （EBL） process for the patterning of photonic crystal waveguides. The whole device structures are exposed in two steps. Holes constituting the photonic crystal lattice and defects are first exposed with a small exposure step size （less than 10nm）. With the introduction of the additional proximity effect to compensate the original proximity effect, the shape, size, and position of the holes can be well controlled. The second step is the exposure of the access waveguides at a larger step size （about 30nm） to improve the scan speed of the EBL. The influence of write-field stitching error can be alleviated by replacing the original waveguides with tapered waveguides at the joint of adjacent write-fields. It is found experimentally that a higher exposure efficiency is achieved with a larger step size;however,a larger step size requires a higher dose.展开更多
We fabricate different-sized Al/AlO_x/Al Josephson junctions by using a simple bridge-free technique, in which only single-layer E-beam resist polymethyl methacrylate（PMMA） is exposed at low accelerate voltage（belo...We fabricate different-sized Al/AlO_x/Al Josephson junctions by using a simple bridge-free technique, in which only single-layer E-beam resist polymethyl methacrylate（PMMA） is exposed at low accelerate voltage（below 30 kV） and the size of junction can be varied in a large range. Compared with the bridge technique, this fabrication process is very robust because it can avoid collapsing the bridge during fabrication. This makes the bridge-free technique more popular to meet different requirements for Josephson junction devices especially for superconducting quantum bits.展开更多
Monte Carlo simulation of paths of a large number of impinging electrons in a multi-layered solid allows defining area of spreading electrons (A) to capture overall behavior of the solid. This parameter “A” follows ...Monte Carlo simulation of paths of a large number of impinging electrons in a multi-layered solid allows defining area of spreading electrons (A) to capture overall behavior of the solid. This parameter “A” follows power law with electron energy. Furthermore, change in critical energies, which are minimum energies loses corresponding to various electrons, as a function of variation in lateral distance also follows power law nature. This power law behavior could be an indicator of how strong self-organization a solid has which may be used in monitoring efficiency of device fabrication.展开更多
We designed and fabricated two types of binary diffractive lenses using Electron beam lithography (EBL) on optical films film for controlling LED light. In the case of the binary diffractive convex lens with 2-mm foca...We designed and fabricated two types of binary diffractive lenses using Electron beam lithography (EBL) on optical films film for controlling LED light. In the case of the binary diffractive convex lens with 2-mm focal length, it is possible to control the luminous intensity distribution. To improve the diffraction efficiency and realize a thin LED light source, the binary diffractive lenses with 100-μm-order focal length are effective. Furthermore we fabricated and characterized the binary diffractive concave lenses for application in LED lighting. It is found that white-light LEDs are strongly diffused by using the binary diffractive concave lenses.展开更多
We demonstrated techniques toward nanoscale thermometries by using a hydrothermally prepared single Sb2Se3 nanowire. Suitable electrodes were fabricated to make electrical contact with a nanowire on a silicon substrat...We demonstrated techniques toward nanoscale thermometries by using a hydrothermally prepared single Sb2Se3 nanowire. Suitable electrodes were fabricated to make electrical contact with a nanowire on a silicon substrate by combining techniques of dielectrophoresis, electron beam (e-beam) lithography, and focused ion beam (FIB). Measurements of temperature-dependent electrical resistivity were carried out from room temperature up to 525 K. The current-voltage characteristics showed linear and symmetric behavior through the entire temperature range, which indicated that the contacts are ohmic. The resistance of the single Sb2Se3 nanowire decreased with increasing temperature. However, a larger thermal activation energy of ~ 4.2 eV was found near a temperature above 420 K. We speculate that the reduction of resistance at a higher temperature was due to the breakdown of grain boundary barriers.展开更多
文摘We present an all-e-beam lithography （EBL） process for the patterning of photonic crystal waveguides. The whole device structures are exposed in two steps. Holes constituting the photonic crystal lattice and defects are first exposed with a small exposure step size （less than 10nm）. With the introduction of the additional proximity effect to compensate the original proximity effect, the shape, size, and position of the holes can be well controlled. The second step is the exposure of the access waveguides at a larger step size （about 30nm） to improve the scan speed of the EBL. The influence of write-field stitching error can be alleviated by replacing the original waveguides with tapered waveguides at the joint of adjacent write-fields. It is found experimentally that a higher exposure efficiency is achieved with a larger step size;however,a larger step size requires a higher dose.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0301802)the National Natural Science Foundation of China(Grant Nos.11474152,91321310,11274156,11504165,and 61521001)
文摘We fabricate different-sized Al/AlO_x/Al Josephson junctions by using a simple bridge-free technique, in which only single-layer E-beam resist polymethyl methacrylate（PMMA） is exposed at low accelerate voltage（below 30 kV） and the size of junction can be varied in a large range. Compared with the bridge technique, this fabrication process is very robust because it can avoid collapsing the bridge during fabrication. This makes the bridge-free technique more popular to meet different requirements for Josephson junction devices especially for superconducting quantum bits.
文摘Monte Carlo simulation of paths of a large number of impinging electrons in a multi-layered solid allows defining area of spreading electrons (A) to capture overall behavior of the solid. This parameter “A” follows power law with electron energy. Furthermore, change in critical energies, which are minimum energies loses corresponding to various electrons, as a function of variation in lateral distance also follows power law nature. This power law behavior could be an indicator of how strong self-organization a solid has which may be used in monitoring efficiency of device fabrication.
文摘We designed and fabricated two types of binary diffractive lenses using Electron beam lithography (EBL) on optical films film for controlling LED light. In the case of the binary diffractive convex lens with 2-mm focal length, it is possible to control the luminous intensity distribution. To improve the diffraction efficiency and realize a thin LED light source, the binary diffractive lenses with 100-μm-order focal length are effective. Furthermore we fabricated and characterized the binary diffractive concave lenses for application in LED lighting. It is found that white-light LEDs are strongly diffused by using the binary diffractive concave lenses.
文摘We demonstrated techniques toward nanoscale thermometries by using a hydrothermally prepared single Sb2Se3 nanowire. Suitable electrodes were fabricated to make electrical contact with a nanowire on a silicon substrate by combining techniques of dielectrophoresis, electron beam (e-beam) lithography, and focused ion beam (FIB). Measurements of temperature-dependent electrical resistivity were carried out from room temperature up to 525 K. The current-voltage characteristics showed linear and symmetric behavior through the entire temperature range, which indicated that the contacts are ohmic. The resistance of the single Sb2Se3 nanowire decreased with increasing temperature. However, a larger thermal activation energy of ~ 4.2 eV was found near a temperature above 420 K. We speculate that the reduction of resistance at a higher temperature was due to the breakdown of grain boundary barriers.
