深反应离子刻蚀(DRIE)工艺在目前的硅微机械高深宽比结构加工中应用十分广泛。在SOI硅片DRIE刻蚀过程中,存在着一些被认为对刻蚀速率和结构轮廓不利的效应,如横向刻蚀(Notching)效应。通过在结构旁布置牺牲结构-硅岛,利用Notching效应...深反应离子刻蚀(DRIE)工艺在目前的硅微机械高深宽比结构加工中应用十分广泛。在SOI硅片DRIE刻蚀过程中,存在着一些被认为对刻蚀速率和结构轮廓不利的效应,如横向刻蚀(Notching)效应。通过在结构旁布置牺牲结构-硅岛,利用Notching效应加工出以悬空硅作为敏感单元的风速仪,其响应时间常数和电阻温度系数TCR(Temperature Coefficient of Resistant)分别为1.08μs和4 738×10-6/℃。正如所描述的,对于特定的微机械应用,Notching效应可以转变为一种加工优势,提高了微加工过程中的变化性。展开更多
A metal-assisted method is proposed for the evaluation of gases’molecular abundance ratio in fiber-optic laser-induced breakdown spectroscopy(FO-LIBS).This method can reduce the laser ablation energy and make gas com...A metal-assisted method is proposed for the evaluation of gases’molecular abundance ratio in fiber-optic laser-induced breakdown spectroscopy(FO-LIBS).This method can reduce the laser ablation energy and make gas composition identification possible.The principle comes from the collision between the detected gases and the plasma produced by the laser ablation of the metal substrate.The interparticle collision in the plasma plume leads to gas molecules dissociating and sparking,which can be used to determine the gas composition.The quantitative relationship between spectral line intensity and molecular abundance ratio was developed over a large molecular abundance ratio range.The influence of laser ablation energy and substrate material on gas quantitative calibration measurement is also analyzed.The proposed metal-assisted method makes the measurement of gases’molecular abundance ratios possible with an FO-LIBS system.展开更多
The transverse electro-optic（EO）modulation system is built based on cubic boron nitride（cBN）single crystals unintentionally doped and synthesized at a high pressure and high temperature.The photoelectric output of...The transverse electro-optic（EO）modulation system is built based on cubic boron nitride（cBN）single crystals unintentionally doped and synthesized at a high pressure and high temperature.The photoelectric output of the system includes two parts that can be measured respectively and the value of elements in the linear EO tensor of the cBN crystal can be obtained.This method does not need to measure the absolute light intensity.All of the surfaces of the tiny cBN crystals whose hardness is next to the hardest diamonds are{111}planes.The rectangular parallelepiped cBN samples are obtained by cleaving along{110}planes and subsequently grinding and polishing{112}planes of the tiny octahedral cBN flakes.Three identical non-zero elements of the EO tensor of the cBN crystal are measured via two sample configurations,and the measured results are very close,about 3.68 and 3.95 pm/V,respectively,which are larger than the linear EO coefficients of the general III-V compounds.展开更多
文摘深反应离子刻蚀(DRIE)工艺在目前的硅微机械高深宽比结构加工中应用十分广泛。在SOI硅片DRIE刻蚀过程中,存在着一些被认为对刻蚀速率和结构轮廓不利的效应,如横向刻蚀(Notching)效应。通过在结构旁布置牺牲结构-硅岛,利用Notching效应加工出以悬空硅作为敏感单元的风速仪,其响应时间常数和电阻温度系数TCR(Temperature Coefficient of Resistant)分别为1.08μs和4 738×10-6/℃。正如所描述的,对于特定的微机械应用,Notching效应可以转变为一种加工优势,提高了微加工过程中的变化性。
基金supported by the National Key R&D Program of China(No.2017YFC1200400)the Development Fund of Institute of Fluid Physics,China Academy of Engineering Physics(No.SFZ20150302)。
文摘A metal-assisted method is proposed for the evaluation of gases’molecular abundance ratio in fiber-optic laser-induced breakdown spectroscopy(FO-LIBS).This method can reduce the laser ablation energy and make gas composition identification possible.The principle comes from the collision between the detected gases and the plasma produced by the laser ablation of the metal substrate.The interparticle collision in the plasma plume leads to gas molecules dissociating and sparking,which can be used to determine the gas composition.The quantitative relationship between spectral line intensity and molecular abundance ratio was developed over a large molecular abundance ratio range.The influence of laser ablation energy and substrate material on gas quantitative calibration measurement is also analyzed.The proposed metal-assisted method makes the measurement of gases’molecular abundance ratios possible with an FO-LIBS system.
基金supported by the National Natural Science Foundation of China(Nos.60976037 and61077026)the Joint Research Project of NSFC-RFBR(No.61111120097)the National High-Technology Research and Development Program of China(No.2009AA03Z419)
文摘The transverse electro-optic（EO）modulation system is built based on cubic boron nitride（cBN）single crystals unintentionally doped and synthesized at a high pressure and high temperature.The photoelectric output of the system includes two parts that can be measured respectively and the value of elements in the linear EO tensor of the cBN crystal can be obtained.This method does not need to measure the absolute light intensity.All of the surfaces of the tiny cBN crystals whose hardness is next to the hardest diamonds are{111}planes.The rectangular parallelepiped cBN samples are obtained by cleaving along{110}planes and subsequently grinding and polishing{112}planes of the tiny octahedral cBN flakes.Three identical non-zero elements of the EO tensor of the cBN crystal are measured via two sample configurations,and the measured results are very close,about 3.68 and 3.95 pm/V,respectively,which are larger than the linear EO coefficients of the general III-V compounds.
