Based on the frequency-to-time mapping relation of the linearly chirped pulse, the temporal phase shift induced by a laser-excited wake in a helium gas jet is measured using a chirped-pulse spectral interferometry wi...Based on the frequency-to-time mapping relation of the linearly chirped pulse, the temporal phase shift induced by a laser-excited wake in a helium gas jet is measured using a chirped-pulse spectral interferometry with ～ 140 fs resolution over a temporal region of I ps in a single shot. In this measurement, the image of the wake is obtained with one-dimensional spatial resolution and temporal resolution limited only by the bandwidth and chirp of the pulse. The ＇bubbles＇ feature of the wake structure, along with multiple wakes excited by the main lobe and the side lobe of a laser focal-spot, is captured simultaneously.展开更多
We report an optical spectroscopy study on LaSb, a compound recently identified to exhibit extremely large magnetoresistance. Our optieal measurement indicates that the material has a low carrier density. More inter- ...We report an optical spectroscopy study on LaSb, a compound recently identified to exhibit extremely large magnetoresistance. Our optieal measurement indicates that the material has a low carrier density. More inter- estingly, the study reveals that the plasma frequency increases with decreasing temperature. This phenomenon suggests either an increase of the conducting carrier density or/and a decrease of the effective mass of carriers with decreasing temperature. We attribute it primarily to the latter effect. Two possible scenarios on its physical origin are examined and discussed. The study offers new insight into the electronic structure of this compound.展开更多
The heavy lanthanide ions(Dy,Ho,Er,Tm and Yb)were used to probe the conformation of L-arginine in aqueous solution.The results showed that the contact contribution to the observed^(13)C paramagnetic shift is very smal...The heavy lanthanide ions(Dy,Ho,Er,Tm and Yb)were used to probe the conformation of L-arginine in aqueous solution.The results showed that the contact contribution to the observed^(13)C paramagnetic shift is very small for nuclei four or more bonds away from the bound lanthanide ion and it is significant for those in close proximity to the lanthanide ion.The overall conformation of L-arginine was established by fitting the calculated geometric factors for the corresponding experimental data.In the lanthanide-L-arginine complex,the whole backbone of the ligand is located outsite the zero-dipolar shift cone of the lanthanide ion with the carboxyl group selectively coordinated to the metal.The calculated RE-O distance is 0.21 nm for the bidentate coordination mode and the ligand is in an extended conformation in the solution with the molecular backbone corresponding to the trans form.展开更多
For thick resist implant layers,such as a high voltage P well and a deep N well,systematic and uncorrectable overlay residues brought about by the tapered resist profiles were found.It was found that the tapered profi...For thick resist implant layers,such as a high voltage P well and a deep N well,systematic and uncorrectable overlay residues brought about by the tapered resist profiles were found.It was found that the tapered profile is closely related to the pattern density.Potential solutions of the manufacturing problem include hardening the film solidness or balancing the exposure density.In this paper,instead of focusing on the process change methodology,we intend to solve the issue of the overlay metrology error from the perspective of the overlay mark design.Based on the comparison of the overlay performances between the proposed overlay mark and the original design,it is shown that the optimized overlay mark target achieves better performance in terms of profiles,dynamic precision,tool induced shift（TIS）,and residues.Furthermore,five types of overlay marks with dummy bars are studied,and a recommendation for the overlay marks is given.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 61377102the Defense Industrial Technology Development Program under Grant No B1520133010
文摘Based on the frequency-to-time mapping relation of the linearly chirped pulse, the temporal phase shift induced by a laser-excited wake in a helium gas jet is measured using a chirped-pulse spectral interferometry with ～ 140 fs resolution over a temporal region of I ps in a single shot. In this measurement, the image of the wake is obtained with one-dimensional spatial resolution and temporal resolution limited only by the bandwidth and chirp of the pulse. The ＇bubbles＇ feature of the wake structure, along with multiple wakes excited by the main lobe and the side lobe of a laser focal-spot, is captured simultaneously.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11327806 and GZ1123the National Key Research and Development Program of China under Grant No 2016YFA0300902
文摘We report an optical spectroscopy study on LaSb, a compound recently identified to exhibit extremely large magnetoresistance. Our optieal measurement indicates that the material has a low carrier density. More inter- estingly, the study reveals that the plasma frequency increases with decreasing temperature. This phenomenon suggests either an increase of the conducting carrier density or/and a decrease of the effective mass of carriers with decreasing temperature. We attribute it primarily to the latter effect. Two possible scenarios on its physical origin are examined and discussed. The study offers new insight into the electronic structure of this compound.
基金This project was supported by the Natural Science Foundation of China
文摘The heavy lanthanide ions(Dy,Ho,Er,Tm and Yb)were used to probe the conformation of L-arginine in aqueous solution.The results showed that the contact contribution to the observed^(13)C paramagnetic shift is very small for nuclei four or more bonds away from the bound lanthanide ion and it is significant for those in close proximity to the lanthanide ion.The overall conformation of L-arginine was established by fitting the calculated geometric factors for the corresponding experimental data.In the lanthanide-L-arginine complex,the whole backbone of the ligand is located outsite the zero-dipolar shift cone of the lanthanide ion with the carboxyl group selectively coordinated to the metal.The calculated RE-O distance is 0.21 nm for the bidentate coordination mode and the ligand is in an extended conformation in the solution with the molecular backbone corresponding to the trans form.
文摘For thick resist implant layers,such as a high voltage P well and a deep N well,systematic and uncorrectable overlay residues brought about by the tapered resist profiles were found.It was found that the tapered profile is closely related to the pattern density.Potential solutions of the manufacturing problem include hardening the film solidness or balancing the exposure density.In this paper,instead of focusing on the process change methodology,we intend to solve the issue of the overlay metrology error from the perspective of the overlay mark design.Based on the comparison of the overlay performances between the proposed overlay mark and the original design,it is shown that the optimized overlay mark target achieves better performance in terms of profiles,dynamic precision,tool induced shift（TIS）,and residues.Furthermore,five types of overlay marks with dummy bars are studied,and a recommendation for the overlay marks is given.
