Poly(styrene-γ-methacrylic propyl trimethoxysilane)/MCM-41 [P(St-MPS)/MCM-41] core-shell composite microspheres functionalized by Carbon-carbon double bond group were directly obtained by co-condensation synthesis method in soap-free emulsion using cetyltrimethyl ammonium bromide and P(St-MPS) microspheres as co-templates,P(St-MPS) microspheres,tetraethyl orthosilicate and MPS as silica source.The synthesized samples were characterized by XRD,TEM and FT-IR.The results show that functionalized P(St-MPS)/MCM-41 core-shell composite microspheres are synthesized by one step directly in soap-free emulsion.The diameter of the functionalized P(St-MPS)/MCM-41 core-shell composite microspheres and the thickness of the shell were about 260 nm and 10 nm,respectively.
The microelectromechanical system(MEMS) packaging technology is a key technique for MEMS based on microelectronics packaging.Function,some particularities and classification of MEMS packaging technologies are put forward,some important and advanced technologies of MEMS packaging are introduced,such as bonding technology,top bottom ball grid array technology(TB-BGA),flip-chip technology(FCT),multi-chip packaging(MCP) technology and three dimensions(3-D) technology.Finally,the trends of development and research for MEMS packaging are discussed.
The method of vertical scan is widely used in ion implanters.This paper introduces the structure and design of an improved long vertical scan system.The results show that this system can improve the reliability and stability of mechanical scan in an ion implanter.
A sort of impact resistant micro-acceleration sensor based on SOI was designed, which solved the problem of insulation leakage when piezoresistive MEMS-accelerometer sensor work in high temperature, this enlarged range of the circumstance temperature effectively. Blue print make craft work to carry out by applying advanced technique such as LIGA, ICP. This research provides guide line for manufacture of high-level piezoresistive sensor in the future.
The ZnO green tapes were fabricated successfully,which had high strength,good flexibility,homogeneous microstructure and laminated under room temperature through aqueous tape casting with styrene-acrylic latex as binders.On the base of pressure sensitive adhesion of styrene-acrylic latex,the ZnO multi-layers varistor materials are produced by room temperature laminated processing.After sintered the ZnO multi-layers body,the largest relative density can reach 99.85%,with the sintering temperature increasing,the breakdown voltage of unit thickness declines,the minimum of leakage current is 0.3 μ A.The ZnO materials with the best sinterability and varistor property have been successfully produced by the aqueous tape casting processing that are obviously better than drying-pressure processing.
In order to improve the combustion property in the micro combustor,the problems in the micro combustor are analyzed and the relevant measures are put forward. Based on the characteristic of MEMS technology and micro combustors,the structure of the micro combustor is ameliorated by the methods of rotational flow,adding premixing channels and export channels and predigesting devices for pipe connection.The results show the premix time(efficiency) of fuel and air is enhanced in the premixed chamber.It can make full use of the gas heat and increase the initial temperature of premix gas and reduce heat emission of the micro combustor,which is be favorable for the fire of fuel.The burning time of fuel and air is prolonged and gas disturbance is intensified in the combustion chamber. The device connecting pipes of the micro combustor and gas sources is designed,which predigests the connect problems of pipes and is convenient for the installation of pipes and is easier to ensure gas tight.This research will lay the foundation for the next experimental investigation about premix、catalytic reforming and combustion of fuel and air in the micro combustor.
High quality Al doped ZnO(AZO) thin films were deposited on glass substrates by direct current(DC) reactive sputtering using a Zn target(99.99%) containing Al of 1.5%.The compositional and element valence state analysis of the annealed AZO thin films have been investigated by X-ray photoelectron spectroscopy(XPS).The electrical properties of AZO thin films have been measured by Van der Pauw method.The experiment results show that Zn and Al atoms lie in the oxidized state,O atoms mainly lie in the crystal lattice positions or adsorbed.The annealing temperature and the ratio of oxygen to argon have strong influence on the electrical properties of AZO thin films.With increasing the annealing temperature,electrical resistivity decreased,but carrier concentration and mobility increased.Moreover,with increasing the ratio of oxygen to argon,electrical resistivity increased,while mobility decreased.Therefore,it is obtained that the optimal oxygen argon ratio and annealing temperature of AZO thin films by direct current reactive magnetron sputtering is 0.3/27 and 400 ℃,respectively.Under this preparation conditions,the resistivity of AZO thin films can decrease to 10-4 Ω·cm and carrier concentration of AZO thin films is up to 1 020 cm-3.
The design principle and the fabrication process of color separation gratings are studied.The 300 μm period CSG in a fused silica substrate(100 mm×100 mm) was fabricated by using a lithographic process and the ion-beam etching with beam energy of 450 eV and beam density of 80 mA/mc2 at 30 ° angle of incidence.The normalized 3 ω zeroth-order transmission efficiency of CSG is measured about 91.9%.The results show that it is feasible to fabricate CSG with high diffraction efficiency by the fabrication process which offers great dimensional control and steeper pattern sidewall,and it gives some useful references to fabrication the CSG with higher diffraction efficiency.
Upgrading the system resolution power is one of the most importance things in two-photon micro-fabrication research.According to the theory on two-photon micro-fabrication,we are able to reveal the relation between the and resolution of fabrication system.Then,the method to enhance the resolution of two-photon fabrication by optimizing the techniques characters is discussed,accompanied with the experimental support.Next,the proposal that using the diffractive optical element to modulate the wave front distribution and improve the resolution is proposed,which is designed in theory and verified in experience.
By the method of chemical co-precipitation,the microstructral research and electrochemical performance tests discovered that the value of a aix and c becoming bigger with rising Zn2+content and lowing PO43-content,when the mole ratio of PO43-and Zn2+ in the sample material respectively were 5.21% and 23.4%,the sample was made as the nickel electrode active material,to assemble MH-Ni simulation battery,electrochemical impedance and diffusing impedance are much smaller,at the rate 80 mA/g charged for 5 h under contant current,discharge at rate 40 mA/g,the final voltage was controlled at the 1.0 V,the electrode material was stable in the strong alkia solution and during the charging and discharging 30 times circulations,whose discharge platform 1.34 V was higher,the discharge specific capacity reached 335.31 mAh/g,the rate of sustaining specific capacity was 94%.
The cathode material LiNi0.4Co0.2Mn0.4O2 for lithium ion battery was prepared by carbonate co-precipitation method.X-ray diffraction(XRD),scanning electron microscopy(SEM) and electrochemical tests were used to characterize structure,appearance and electrochemical performances of LiNi0.4Co0.2Mn0.4O2.It was found that the sample synthesized at 800 ℃ for 12 h is homogenous distribution of particles.Electrochemical test shows that the initial discharge capacity of LiNi0.4Co0.2Mn0.4O2 powder is 151 mAh·g-1 at the rate of 0.2 C,and the capacity retains 138 mAh·g-1 after 30 cycles.
The Cu-doped ZnO films were prepared by the radio frequency(RF) magnetron sputtering techniqueon ITO glass and quartz substrates.The structure and light transmittance of Cu-doped ZnO films were discussed in details.The results indicate that Cu doping enhances the intensity of the ZnO(002) peak.The transmittance of the Cu-doped ZnO films are decreased with the increasing of Cu content.In additional,electric resistivity increases with the increasing of Cu content.
In wafer cleaning techniques,conventional cleaning mediums are difficult to go deep into tiny trenches on IC chips due to the surface tension of aqua.The unavoidable desiccation process after wet cleaning would bring granule adsorption and structure distortion or invalidation because of the surface tension caused by the gas/liquid interface.Cleaning technology based on supercritical carbon dioxide is the best way to conquer the mentioned embarrassments.Supercritical carbon dioxide green IC cleaning apparatus could implement zero-surface tension cleaning/desiccation,and sacrificial layer release.The apparatus,a kind of green semiconductor manufacturing equipment,is a low-cost,high-yield rate,and carbon dioxide-cycle apparatus.
为了制备高线密度X射线透射光栅掩模,分析了电子束光刻中场拼接对高线密度光栅图形的影响;利用几何校正技术和低灵敏度的950 k的PMMA电子束抗蚀剂,克服了电子束的邻近效应对厚胶图形曝光的影响.采用电子束光刻和微电镀的方法制备了5 000line/mm x射线透射光栅的掩模,并将栅线宽度精确控制在100 nm～110 nm,为X射线光刻复制高线密度X射线透射光栅创造了有利条件.
采用化学反应共沉淀法制备出Zn2+和PO43-阴阳离子复合掺杂的α-Ni(OH)2粉体材料.通过对其微结构表征和电化学性能的测试分析结果表明,随着阳离子Zn2+含量相对增加,阴离子PO43-含量相对减少,晶胞参数α和C逐渐增大,当把掺入Zn2+,PO43-的摩尔百分比为23.4%,5.21%时的α-Ni(OH)2样品作为MH-Ni电池的正极活性材料时,电化学阻抗和扩散电阻较小,电池在以80 mA/g恒电流充电5 h,40 mA/g恒电流放电,终止电压为1.0 V的充放电制度下,具有1.34 V较高的放电中值电压,放电比容量为335.31 mA·h·g-1,而且在强碱溶液中稳定存在,30次充放电循环后没有相变化,放电比容量保持率为94%.
The design principle of computer-generated-holograms(CGHs) was introduced and the key fabrication technique was studied.Algorithms and software for the generation of CGH lithography patterns were developed independently and the technique for fabricating large-area,nonperiodical,complex lithography patterns employing high-speed electron beam lithography system was studied.With additional processes of wet etching of chrome and ICP etching of fused silica,the phase-type CGH with a diameter of 64 mm,an outermost line-width of 2.0 μm and an etching depth of 690 nm is fabricated.Measurements of a fabricated CGH are carried out,and the measurement result shows that high-quality CGHs can be fabricated by this process and the quality of the CGH meets the requirements of application.
The fiber laser is used to cut Co-Cr alloy cannula by changing of the aid-air, air pressure,pulse width and cutting speech in order to view the actions of the cut quality.Then the frequency tripled Nd∶YAG laser is applied to cut the same material and the two cutting results were compared.It is found that using Ar or N2 as aid-air is better than using compress air,there is a best air pressure exit,the more reduce of the pulse width the better,and there is a nonlinear inverse ratio between the cutting rate and the width of cutting.And it is also found that frequency tripled Nd∶YAG laser is better than fiber laser when use for micro-cutting.
As a promising technology,it has significant advantages for low-volume manufacturing,high resolution required,research,design verification and the exploration of novel applications of lithography.The present and the problem of the maskless lithography wereintroduced.By comparing several familiar maskless lithography technologies,some results were acquired.Scanning electron-beam lithography (SEBL) systems have high resolution but low-volume manufacturing.Zone-plate-array lithography (ZPAL) has produced extensive theoretic and experi mental results,it will be usedin making masktool for its’highresolution and as a complement to SEBL.
Nanocrystalline α-Fe2O3 was prepared by low temperature combustion synthesis method using ferric nitrate and polyvinyl alcohol(PVA).Nanocrystalline αFe2O3 was characterized by XRD,SEM,TEM and EDS.The results showed that α-Fe2O3 particle edges are smooth and have uniform particle size distribution with full reaction of combustion when the mole ratio of ferric nitrate to polyvinyl alcohol is 1 to 0.5,and the products present red granular substances.The gels which got from at 150 ℃ were ignited at 450 ℃.After calcining the reaction at 450 ℃ for 1.5 h,α-Fe2O3 were obtained and have a little γ-Fe2O3.Characterized By TEM,XRD and Clouter N4 Plus Submicron Sizer for particle size,the grain size is measured in the range from 20 nm to 50 nm.
When Boron and Phosphorous had been alternately implanted with the same implanter,the PF molecules would be generated,due to the P+ residue reacted with F cracked from BF3.It is pointed out that the average mass of dopant into the wafer following normal distribution,with the target dopant mass as center value.The potential overlap area between the distributions of 49BF2+ and 50PF+ was the root cause of phosphorus contamination.In order to prevent PF contamination real time,the precision of mass analyzer had been improved.When the beam current is increased to be 800 μA,It is found that the implanter couldn't detect PF with mass analyzer's AMU setting at 49±0.5.After 80 h P+ and alternately specie implanted,worse experiments had been studied on the implanter.When the arc current is 3 100 μA,the result of sheet resistance indicates that no PF found by setting AMU at 49±0.3(m/Δm=169.3).Four parameters of worse conditions had been combined together to test the solution's reliability as following: worse implanter,higher arc current at 3 100 μA,higher beam current at 800 μA and higher 49BF2+ dosage at 2.2×1015.Even with the combined worse conditions,the analysis result of SIMS showed that no Phosphorus peak found for two samples by setting AMU at 49±0.3.This solution is proved to be effective during the mass production by controlled the AMU setting value of improved mass analyzer,so it is not necessary to the keep the original high cost solution by Frederic Sahores(2002 IEEE),such as increasing the frequence of cleaning or dedicated one implanter to one dopant.
