A physical model for simulating overlay metrology employing diffraction based overlay(DBO)principles is built.It can help to optimize the metrology wavelength selection in DBO.Simulation result of DBO metrology with a...A physical model for simulating overlay metrology employing diffraction based overlay(DBO)principles is built.It can help to optimize the metrology wavelength selection in DBO.Simulation result of DBO metrology with a model based on the finite-difference time-domain(FDTD)method is presented.A common case(bottom mark asymmetry)in which error signals are always induced in DBO measurement due to the process imperfection were discussed.The overlay sensitivity of the DBO measurement across the visible illumination spectrum has been performed and compared.After adjusting the model parameters compatible with the actual measurement conditions,the metrology wavelengths which provide the accuracy and robustness of DBO measurement can be optimized.展开更多
Air pollution and climate change are two important threats facing in our planet and are tightly linked to carbonaceous components in the atmosphere.A better understanding of the emission sources and environmental fate...Air pollution and climate change are two important threats facing in our planet and are tightly linked to carbonaceous components in the atmosphere.A better understanding of the emission sources and environmental fate/sink of carbonaceous components is critical for improving our knowledge of the global carbon cycle and mitigating the negative environmental impacts of air pollution and climate change on human well-being.Radiocarbon(^(14)C),which is decayed completely in fossil fuel(e.g.coal and petroleum),is an ideal tool for quantifying the carbon flow in various carbon reservoirs.This study reviews the current knowledge of 14C in organic carbon(OC),elemental carbon(EC),individual organic compounds,methane(CH_(4)),carbon dioxide(CO_(2)),annual plants,and tree rings.The impacts of fossil and non-fossil sources on the atmosphere can be quantified by measuring^(14)C.We also report on the influence of nuclear power plants and sea-air gas exchange on the abundance of^(14)C in the atmosphere.The increasing fossil fuel emissions indicated by the depletion of^(14)CO_(2)under IPCC RCP scenarios,support the urgent need to devise ambitious strategies of reducing carbonaceous components to achieve sustainable development on Earth.This review summarizes the challenges and perspectives of 14C studies of the atmosphere.展开更多
基金supported by the National Science and Technology Major Project of China (Grant No. 2016ZX02301001)
文摘A physical model for simulating overlay metrology employing diffraction based overlay(DBO)principles is built.It can help to optimize the metrology wavelength selection in DBO.Simulation result of DBO metrology with a model based on the finite-difference time-domain(FDTD)method is presented.A common case(bottom mark asymmetry)in which error signals are always induced in DBO measurement due to the process imperfection were discussed.The overlay sensitivity of the DBO measurement across the visible illumination spectrum has been performed and compared.After adjusting the model parameters compatible with the actual measurement conditions,the metrology wavelengths which provide the accuracy and robustness of DBO measurement can be optimized.
基金This research was supported by the National Natural Science Foundation of China(Nos.42030715,41877349)Guangdong Foundation for Program of Science and Technology Research(Nos.2017BT01Z134,2019B121205006)National Key R&D Program of China(2017YFC0212000).
文摘Air pollution and climate change are two important threats facing in our planet and are tightly linked to carbonaceous components in the atmosphere.A better understanding of the emission sources and environmental fate/sink of carbonaceous components is critical for improving our knowledge of the global carbon cycle and mitigating the negative environmental impacts of air pollution and climate change on human well-being.Radiocarbon(^(14)C),which is decayed completely in fossil fuel(e.g.coal and petroleum),is an ideal tool for quantifying the carbon flow in various carbon reservoirs.This study reviews the current knowledge of 14C in organic carbon(OC),elemental carbon(EC),individual organic compounds,methane(CH_(4)),carbon dioxide(CO_(2)),annual plants,and tree rings.The impacts of fossil and non-fossil sources on the atmosphere can be quantified by measuring^(14)C.We also report on the influence of nuclear power plants and sea-air gas exchange on the abundance of^(14)C in the atmosphere.The increasing fossil fuel emissions indicated by the depletion of^(14)CO_(2)under IPCC RCP scenarios,support the urgent need to devise ambitious strategies of reducing carbonaceous components to achieve sustainable development on Earth.This review summarizes the challenges and perspectives of 14C studies of the atmosphere.
