In this paper,we report the study of the process of fabricating a multi-layermetal micro-structure using UV-LIGA overlay technology,includingmask fabrication,substrate treatment,and UV-LIGA overlay processes.To solve ...In this paper,we report the study of the process of fabricating a multi-layermetal micro-structure using UV-LIGA overlay technology,includingmask fabrication,substrate treatment,and UV-LIGA overlay processes.To solve the process problems in the masking procedure,the swelling problemof the first layer of SU-8 thick photoresist was studied experimentally.The 5μmline-width compensation and closed 20μmand 30μmisolation strips were designed and fabricated around the micro-structure pattern.The pore problemin the Ni micro-electroforming layer was analyzed and the electroforming parameters were improved.The pH value of the electroforming solution should be controlled between 3.8 and 4.4 and the current density should be below 3 A/dm^2.To solve the problems of high inner stress and incomplete development of the micro-cylinder hole array with a diameter of 30μm,the lithography process was optimized.The pre-baking temperature was increased via gradient heating and rose every 5℃ from 65℃ to 85℃ and then remained at 85℃ for 50 min–1 h.In addition,the full contact exposure was used.Finally,a multi-layer metal micro-structure with high precision and good quality of microelectroforming layer was fabricated using UV-LIGA overlay technology.展开更多
Three different kinds of PELE(the penetrator with lateral efficiency) were launched by ballistic artillery to impact the multi-layer spaced metal target plates.The lmpact velocities of the projectiles were measured by...Three different kinds of PELE(the penetrator with lateral efficiency) were launched by ballistic artillery to impact the multi-layer spaced metal target plates.The lmpact velocities of the projectiles were measured by the velocity measuring system.The damage degree and process of each laye r of target plate impacted by the three kinds of projectiles were analyzed.The experimental results show that all the three kinds of projectiles have the effect of expanding holes on the multi-layer spaced metal target plates.For the normal structure PELE(without layered) with tungsten alloy jacket and the radial layered PELE with tungsten alloy jacket,the diameters of holes on the seco nd layer of plates are 3.36 times and 3.76 times of the diameter of the projectile,re spectively.For radial layered PELE with W/Zr-based amorphous composite jacket,due to the large number of tungsten wires dispersed after the impact,the diameter of the holes on the four-layer spaced plates can reach 2.4 times,3.04 times,5.36 times and 2.68 times of the diameter of the projectile.Besides,the normal structure PELE with tungsten alloy jacket and the radial layered PELE whit tungsten alloy jacket formed a large number of fragments impact marks on the third target plate.Although the number of fragments penetrating the third target plate is not as large as that of the normal structure PELE,the area of dispersion of fragments impact craters on the third target plate is larger by the radial layered PELE.The radial layered PELE with W/Zr-based amorphous composite jacket released a lot of heat energy due to the impact of the matrix material,and formed a large area of ablation marks on the last three target plates.展开更多
We present a design method for calculating and optimizing sound absorption coefficient of multi-layered porous fibrous metals （PFM） in the low frequency range. PFM is simplified as an equivalent idealized sheet with...We present a design method for calculating and optimizing sound absorption coefficient of multi-layered porous fibrous metals （PFM） in the low frequency range. PFM is simplified as an equivalent idealized sheet with all metallic fibers aligned in one direction and distributed in periodic hexagonal patterns. We use a phenomenological model in the literature to investigate the effects of pore geometrical parameters （fiber diameter and gap） on sound absorption performance. The sound absorption coefficient of multi- layered PFMs is calculated using impedance translation theorem, To demonstrate the validity of the present model, we compare the predicted results with the experimental data. With the average sound absorption （low frequency range） as the objective function and the fiber gaps as the design variables, an optimization method for multi-layered fibrous metals is proposed. A new fibrous layout with given porosity of multi-layered fibrous metals is suggested to achieve optimal low frequency sound absorption. The sound absorption coefficient of the optimal multi-layered fibrous metal is higher than the single- layered fibrous metal, and a significant effect of the fibrous material on sound absorption is found due to the surface Dorosity of the multi-layered fibrous.展开更多
Laser multi\|layer cladding experiments were performed on the substrate of DD3 single crystal with FGH95 powder as cladding material.The solidification microstructure in the sample was investigated.It was found that t...Laser multi\|layer cladding experiments were performed on the substrate of DD3 single crystal with FGH95 powder as cladding material.The solidification microstructure in the sample was investigated.It was found that the solidification microstructure was greatly influenced by the crystallography orientation of the substrate and the local solidification conditions.When the angle between the preferred orientation of the single crystal and the direction of heat flow in the cladding layer is less than 30°,single crystal cladding layers were acquired.Otherwise the crystallography orientation of the cladding layer will deviate from the orientation of the substrate and the microstructure with polycrystalline appears.Meanwhile,even when the experiments were performed on the same preferred crystal surface,the solidification microstructures will be different distinctly resulting from the variation of the local solidification conditions.The secondary arms were degenerated and the primary arm spacing was about 10\|20μm.Further investigation shows that the phases of the cladding layer are mainly made up ofγ,γ′,the flower\|likeγ/γ′eutectic and carbide.The morphology ofγ′was cubical and the size is less than 0.1μm.展开更多
Straight plates, hollow columns, ear-like blade tips, twist plates withdirectional solidification microstructure made of Rene 95 superalloys were successfully fabricatedon Nickel-base superalloy and DD3 substrates, re...Straight plates, hollow columns, ear-like blade tips, twist plates withdirectional solidification microstructure made of Rene 95 superalloys were successfully fabricatedon Nickel-base superalloy and DD3 substrates, respectively. The processing conditions for productionof the parts with corresponding shapes were obtained. The fabrication precision was high and thecomponents were compact. The solidification microstructure of the parts was analyzed by opticalmicroscopy. The results show that the solidification microstructure is composed of columnardendrites, by epitaxial growth onto the directional solidification substrates. The crystallographyorientation of the parts was parallel to that of the substrates. The primary arm spacing was about10 mum, which is in the range of superfine dendrites, and the secondary arm was small or evendegenerated. It is concluded that the laser metal forming technique provides a method to manufacturedirectional solidification components.展开更多
A metal-insulator-silicon （MIS） capacitor with hemi-spherical grained poly atomic layer deposition （ALD） deposited Al2O3 and multi-layered chemical vapor deposition （CVD） TiN structure is fabricated. The impact ...A metal-insulator-silicon （MIS） capacitor with hemi-spherical grained poly atomic layer deposition （ALD） deposited Al2O3 and multi-layered chemical vapor deposition （CVD） TiN structure is fabricated. The impact of the deposition process and post treatment condition on the MIS capacitor＇s time-dependent dielectric breakdown （TDDB） performance is also studied. With an optimized process, it is confirmed by Auger electron spectroscopy and secondary ion mass spectrometry analysis that the Al（CH3）3/O3-based ALD Al2O3 dielectric film is carbon free and the hydrogen content is as low as 9 × 1019 cm-3. The top electrode TiN is obtained by multi-layered TiCl4/NH3 CVD deposited TiN followed by 120 s post NH3 treatment after each layer. This has higher diffusion barrier in preventing impurity diffusion through TiN into the Al2O3 dielectric due to its smaller grain size. As shown in energy dispersive X-ray analysis, there is no chlorine residue in the MIS capacitor structure. The leakage current of the capacitor is lower than 1 × 10-12 A/cm2. No early failures under stress conditions are found in its TDDB test. The novel MIS capacitor is proven to have excellent reliability for advanced DRAM technology.展开更多
文摘In this paper,we report the study of the process of fabricating a multi-layermetal micro-structure using UV-LIGA overlay technology,includingmask fabrication,substrate treatment,and UV-LIGA overlay processes.To solve the process problems in the masking procedure,the swelling problemof the first layer of SU-8 thick photoresist was studied experimentally.The 5μmline-width compensation and closed 20μmand 30μmisolation strips were designed and fabricated around the micro-structure pattern.The pore problemin the Ni micro-electroforming layer was analyzed and the electroforming parameters were improved.The pH value of the electroforming solution should be controlled between 3.8 and 4.4 and the current density should be below 3 A/dm^2.To solve the problems of high inner stress and incomplete development of the micro-cylinder hole array with a diameter of 30μm,the lithography process was optimized.The pre-baking temperature was increased via gradient heating and rose every 5℃ from 65℃ to 85℃ and then remained at 85℃ for 50 min–1 h.In addition,the full contact exposure was used.Finally,a multi-layer metal micro-structure with high precision and good quality of microelectroforming layer was fabricated using UV-LIGA overlay technology.
基金supported by National Natural Science Foundation of China(Grant No.11802141)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX18_0465)。
文摘Three different kinds of PELE(the penetrator with lateral efficiency) were launched by ballistic artillery to impact the multi-layer spaced metal target plates.The lmpact velocities of the projectiles were measured by the velocity measuring system.The damage degree and process of each laye r of target plate impacted by the three kinds of projectiles were analyzed.The experimental results show that all the three kinds of projectiles have the effect of expanding holes on the multi-layer spaced metal target plates.For the normal structure PELE(without layered) with tungsten alloy jacket and the radial layered PELE with tungsten alloy jacket,the diameters of holes on the seco nd layer of plates are 3.36 times and 3.76 times of the diameter of the projectile,re spectively.For radial layered PELE with W/Zr-based amorphous composite jacket,due to the large number of tungsten wires dispersed after the impact,the diameter of the holes on the four-layer spaced plates can reach 2.4 times,3.04 times,5.36 times and 2.68 times of the diameter of the projectile.Besides,the normal structure PELE with tungsten alloy jacket and the radial layered PELE whit tungsten alloy jacket formed a large number of fragments impact marks on the third target plate.Although the number of fragments penetrating the third target plate is not as large as that of the normal structure PELE,the area of dispersion of fragments impact craters on the third target plate is larger by the radial layered PELE.The radial layered PELE with W/Zr-based amorphous composite jacket released a lot of heat energy due to the impact of the matrix material,and formed a large area of ablation marks on the last three target plates.
基金the support of the National Basic Research Program(973 Program)of China(Grant No.2011CB610304)the National Natural Science Foundation of China(Grant Nos.11332004 and 11402046)+2 种基金China Postdoctoral Science Foundation(No.2015M571296)the 111 Project(B14013)the CATIC Industrial Production Projects(Grant No.CXY2013DLLG32)
文摘We present a design method for calculating and optimizing sound absorption coefficient of multi-layered porous fibrous metals （PFM） in the low frequency range. PFM is simplified as an equivalent idealized sheet with all metallic fibers aligned in one direction and distributed in periodic hexagonal patterns. We use a phenomenological model in the literature to investigate the effects of pore geometrical parameters （fiber diameter and gap） on sound absorption performance. The sound absorption coefficient of multi- layered PFMs is calculated using impedance translation theorem, To demonstrate the validity of the present model, we compare the predicted results with the experimental data. With the average sound absorption （low frequency range） as the objective function and the fiber gaps as the design variables, an optimization method for multi-layered fibrous metals is proposed. A new fibrous layout with given porosity of multi-layered fibrous metals is suggested to achieve optimal low frequency sound absorption. The sound absorption coefficient of the optimal multi-layered fibrous metal is higher than the single- layered fibrous metal, and a significant effect of the fibrous material on sound absorption is found due to the surface Dorosity of the multi-layered fibrous.
基金National Key Basic Research Development Program me of china(No.G2000067205-3)
文摘Laser multi\|layer cladding experiments were performed on the substrate of DD3 single crystal with FGH95 powder as cladding material.The solidification microstructure in the sample was investigated.It was found that the solidification microstructure was greatly influenced by the crystallography orientation of the substrate and the local solidification conditions.When the angle between the preferred orientation of the single crystal and the direction of heat flow in the cladding layer is less than 30°,single crystal cladding layers were acquired.Otherwise the crystallography orientation of the cladding layer will deviate from the orientation of the substrate and the microstructure with polycrystalline appears.Meanwhile,even when the experiments were performed on the same preferred crystal surface,the solidification microstructures will be different distinctly resulting from the variation of the local solidification conditions.The secondary arms were degenerated and the primary arm spacing was about 10\|20μm.Further investigation shows that the phases of the cladding layer are mainly made up ofγ,γ′,the flower\|likeγ/γ′eutectic and carbide.The morphology ofγ′was cubical and the size is less than 0.1μm.
基金This research was financially supported by the National High Technology Research and Development Program of China (No.2001AA337020)the Development Plan of State Key Fundamental Research of China (No. G2000067205-3)
文摘Straight plates, hollow columns, ear-like blade tips, twist plates withdirectional solidification microstructure made of Rene 95 superalloys were successfully fabricatedon Nickel-base superalloy and DD3 substrates, respectively. The processing conditions for productionof the parts with corresponding shapes were obtained. The fabrication precision was high and thecomponents were compact. The solidification microstructure of the parts was analyzed by opticalmicroscopy. The results show that the solidification microstructure is composed of columnardendrites, by epitaxial growth onto the directional solidification substrates. The crystallographyorientation of the parts was parallel to that of the substrates. The primary arm spacing was about10 mum, which is in the range of superfine dendrites, and the secondary arm was small or evendegenerated. It is concluded that the laser metal forming technique provides a method to manufacturedirectional solidification components.
基金supported by the National Natural Science Foundation of China (No.50371033)the Specialized Research Fund for the Doctoral Program of Higher Education (No.20040674009)the Semiconductor Manufacturing International Corporation
文摘A metal-insulator-silicon （MIS） capacitor with hemi-spherical grained poly atomic layer deposition （ALD） deposited Al2O3 and multi-layered chemical vapor deposition （CVD） TiN structure is fabricated. The impact of the deposition process and post treatment condition on the MIS capacitor＇s time-dependent dielectric breakdown （TDDB） performance is also studied. With an optimized process, it is confirmed by Auger electron spectroscopy and secondary ion mass spectrometry analysis that the Al（CH3）3/O3-based ALD Al2O3 dielectric film is carbon free and the hydrogen content is as low as 9 × 1019 cm-3. The top electrode TiN is obtained by multi-layered TiCl4/NH3 CVD deposited TiN followed by 120 s post NH3 treatment after each layer. This has higher diffusion barrier in preventing impurity diffusion through TiN into the Al2O3 dielectric due to its smaller grain size. As shown in energy dispersive X-ray analysis, there is no chlorine residue in the MIS capacitor structure. The leakage current of the capacitor is lower than 1 × 10-12 A/cm2. No early failures under stress conditions are found in its TDDB test. The novel MIS capacitor is proven to have excellent reliability for advanced DRAM technology.
