射频磁控溅射室温下制备ITO薄膜的光学性能研究

靶材为铟锡氧化物(In2O3:SnO2=1:1),用射频磁控溅射法在低温下制备了光电性能优良的ITO薄膜.质量流量计调节Ar气压强为0.2～3.0Pa,氧流量为0～10sccm,并详细探讨了溅射时氩气压强和氧流量变化对ITO薄膜光学性能的影响.结果表明:溅射Ar气压强为0.8Pa,氧流量为2.4sccm时,薄膜的折射率最低n=1.97,较接近增透膜的光学匹配.薄膜厚度为241.5nm时,薄膜的最大透过率为89.4%(包括玻璃基体),方阻为75.9Ω/□,电导率为8.8×10-4Ω·cm.     

反应射频磁控溅射制备高k氧化锆薄膜及介电性能的研究

在氧气和氩气的混合气体中,在O2/Ar混和气总流量固定的条件下,通过调节O2/Ar流量比,采用反应RF磁控溅射法制备了具有高介电常数的氧化锆薄膜。通过透射电子显微镜(TEM)和原子力显微镜(AFM)研究了O2/Ar流量比与薄膜微观组织和结构、表面平整度之间的关系,并测试分析了在不同O2/Ar流量比下溅射沉积的Al/ZrO2/SiO2/n型Si叠层结构的C V特性曲线。实验结果表明O2/Ar流量比与薄膜微观组织和结构有一定的关系。纯氧气氛下沉积的ZrO2薄膜基本上为纳米级的微晶,晶体结构为单斜结构(a=5.17、b=5.26、c=5.3、α=γ=90°,β=80.17°),在O2/Ar流量比为1∶4混合气氛下制备出了具有非晶结构的均质ZrO2薄膜;低的O2/Ar流量比下溅射得到的ZrO2薄膜样片,均方根粗糙度较低,表面平整度较好;在O2/Ar流量比为1∶4左右时,ZrO2薄膜的相对介电常数达到25。     

二氧化锆栅介质薄膜光学及电学特性研究

采用反应RF磁控溅射法在氧气和氩气的混合气氛中制备了具有较高介电常数、较宽光学禁带间隙的ZrO2薄膜。利用变角度光谱椭圆偏振仪研究了不同O2/Ar流量比下制备所得薄膜的厚度、复折射率、复介电常数和吸收系数,估算了薄膜的光学禁带间隙,并测试分析了在不同O2/Ar流量比下溅射沉积的Al/ZrO2/SiO2/n型Si叠层结构的C V、I V特性曲线。通过对O2/Ar流量比分别为1/9、1/4、4/1、1/0工艺条件下溅射沉积ZrO2薄膜的α2与光子能量关系图的拟合,确定了其光学禁带间隙Eg分别为6.27、5.84、6.03、5.92eV,在O2/Ar流量比为1/9、1/4、1/0工艺条件下溅射沉积ZrO2薄膜,其ZrO2/SiO2叠层的有效介电常数keff计算结果分别为14.6、19.6和9.3,漏电流较低(<5.0×10-5A/cm2),其击穿电场强度分别为5.6、6.3、9MV/cm。     

N掺杂Cu2O薄膜的低温沉积及快速热退火研究

采用氧化亚铜(Cu_2O)陶瓷靶,利用射频磁控溅射沉积法在氮气和氩气的混合气氛下制备了N掺杂Cu_2O(Cu_2O∶N)薄膜,并在N_2气氛下对薄膜进行了快速热退火处理,研究了N_2流量和退火温度对Cu_2O∶N薄膜的生长行为、物相结构、表面形貌及光电性能的影响。结果显示,在衬底温度300℃、N_2流量12sccm条件下生长的薄膜为纯相Cu_2O薄膜;在N_2气氛下对预沉积薄膜进行快速热退火处理不影响薄膜的物相结构,薄膜的结晶质量随退火温度(450℃)的升高而显著改善;快速热退火处理能改善薄膜的结晶质量和缺陷,降低光生载流子的散射,增强载流子的传输,预沉积Cu_2O∶N薄膜经400℃退火处理后展示出较好的电性能,薄膜的霍尔迁移率(μ)为27.8cm~2·V~(-1)·s~(-1)、电阻率(ρ)为2.47×10~3Ω·cm。研究表明低温溅射沉积和快速热退火处理能有效改善Cu_2O∶N薄膜的光电性能。     

磁控溅射TiN薄膜的工艺及电学性能研究

采用反应直流磁控溅射法,在Si基底上制备TiN薄膜.研究了溅射沉积过程中溅射气压和Ar/N2气体流量比对TiN薄膜结构及其电学性能的影响,并对试验结果进行了分析.研究发现,在Ar/N2气体流量比为15:1时,TiN薄膜的表面均方根粗糙度和电阻率都为最小.当溅射气压增大时,薄膜厚度减小.当溅射气压为0.3～0.5Pa时,薄膜表面较光滑,电阻率较小.     

RF磁控溅射制备Al_2O_3薄膜及其介电性能研究

以-αAl2O3为靶材,采用射频磁控溅射法制备了非晶Al2O3薄膜。利用X射线衍射仪、扫描电镜、划痕仪、表面粗糙轮廓仪和阻抗仪研究了不同溅射功率和不同溅射气压对薄膜制备的影响,探索了不同溅射功率下制备的Al2O3薄膜的介电常数和介电损耗与频率的关系。试验结果表明,制备的非晶Al2O3薄膜表面平滑致密;随着工作气压的增加,薄膜沉积速率增加;随着溅射功率的增加,Al2O3薄膜的沉积速率和介电常数逐渐增加、介电损耗逐渐减小;随着频率的增加,Al2O3薄膜的介电常数逐渐减小,高频阶段趋于稳定。     

功率密度对中频磁控溅射制备的氧化锌镓薄膜性能的影响

利用中频磁控溅射方法,溅射Ga2O3含量为6.7wt%的氧化锌镓陶瓷靶材,在低温下(约40℃)制备了ZGO薄膜.考察了溅射功率密度对ZGO薄膜的晶体结构、电学和光学性能的影响.结果表明:溅射功率密度对薄膜的结构、红外反射以及导电性能有较大影响.当溅射功率密度为3.58W/cm2,氩气压力为0.8Pa时,薄膜的电阻率低达1.5×10-3Ω·cm,方块电阻为23Ω时,可见光(λ＝400nm～800nm)平均透过率高于90%.     

磁控溅射制备增透ITO薄膜及其性能研究

用射频磁控溅射法在低温下制备了光电性能优良的ITO(In2O3:SnO2=1:1)薄膜。质量流量计调节氩气压强PAr为0.2～3.0Pa,氧流量fO2为0～10sccm,并详细探讨了溅射时PAr和fO2变化对ITO薄膜光学性能的影响。结果表明:fO2的改变引起薄膜中氧空位浓度变化而影响ITO薄膜折射率n;fO2对ITO靶材表面的溅射阀值和对Ar 散射而改变溅射速率。衬底表面粗糙度对ITO薄膜的折射率测量准确性有较大影响。PAr为0.8Pa,fO2为2.4sccm,薄膜厚度为241.5nm时,nmin=1.97,最大透过率为89.4%(包括玻璃基体),方阻为75.9?/□,电阻率为8.8×10-4?·cm。AFM分析表明薄膜表面针刺很少,表面平整(RMS=3.04nm)。     

Ar气氛下直流磁控溅射ITO薄膜的结构和性能

采用直流磁控溅射法在低温、100%Ar的无氧气氛中制备了光电性能优良的铟锡氧化物(ITO,In2O3:SnO2=90:10,质量百分比)薄膜,详细探讨了溅射时改变氩气压强对ITO薄膜结构以及光电性能的影响.结果表明:溅射时氩气压强越小,ITO薄膜的体心立方晶型越完整,导电性越好,但对可见光透过性的影响不大.当氩气压强为0.3Pa时,溅射薄膜性能最佳,其光透过率可达92.9%,电导率为8.9×10-4Ω·cm.     

一种用于低温下瞬态测温的薄膜热偶技术

薄膜热电偶是采用高真空下离子溅射法制成的。从理论上对它的响应时间常数及动态测温误差进行了分析,并附有初步实验结果。从理论分析和实验结果看来,薄膜热电偶在低温下的响应要快于一般结点型热电偶。     

纳米晶体钛基掺钽TiO2薄膜的摩擦磨损性能

采用室温直流反应磁控溅射技术在纳米晶体钛表面制备掺钽TiO2薄膜,研究了掺Ta量对纳米晶体钛基TiO2薄膜摩擦磨损性能的影响。结果表明：在室温模拟人体体液条件下,掺钽TiO2薄膜与不锈钢淬火钢球（Φ4mm）对摩的磨损率为10^-6-10^-5mm^3·m^-1 N^-1级;随着Ta含量的增加,薄膜的摩擦系数和磨损率呈先...     

PDMS低温热解制备有机/无机膜的研究

以聚二甲基硅氧烷(PDMS)为前驱体聚合物, 采用浸渍法在支撑体上涂覆制备PDMS支撑膜, 将其在惰性气氛下350~480℃低温热解, 制备有机/无机膜。考察了制膜工艺条件对膜气体分离性能的影响; 并借助于TG和FT-IR测试手段探讨了PDMS 的热解过程及化学结构的变化; 采用SEM对有机/无机膜的微观形貌进行表征。研究表明, 采用低温热解法可以成功制备出气体分离性能良好的有机/无机膜。该膜既保留了有机膜的柔韧性, 又具有无机膜的热稳定性好的优点, 并表现出良好的气体渗透性能和选择性。PDMS制膜液的浓度、浸渍次数、复合膜的热解温度及基体孔径和性质等因素对有机/无机膜的气体分离性能以及膜层结构有较大的影响。在最佳工艺条件下制备的有机/无机膜其O₂渗透通量为21.2 GPU(1 GPU=7.501×10^-12 m³(STP)/(m²?s?Pa)), O₂/N₂分离系数为2.28。     

硫化物固态电解质Li6PS5Cl的球磨-固相烧结制备与性能

硫银锗矿结构的硫化物固态电解质Li₆PS₅Cl（LPSC）具有离子电导率高（>3×10^-3 S·cm^-1）和对锂稳定性良好等特点,是构建全固态锂离子电池的理想电解质材料之一,具有良好的发展前景。本工作采用高能球磨和惰性气氛固相烧结相结合的方法制备硫银锗矿型固态电解质LPSC,并采用粉末X射线衍射（XRD）、拉曼光谱（Raman spectra）和扫描电子显微镜（SEM）等对其进行表征,探究制备工艺对LPSC结构、成分和电学性质等的影响。结果表明：高能球磨会破坏原料的晶粒,降低晶粒尺寸,延长球磨时间有利于LPSC前驱体粉末的非晶化和后续烧结,提高烧结温度将促进制备的LPSC电解质的物相变纯和离子电导率升高,但烧结温度过高会导致LPSC的分解。综合考虑球磨时间和烧结温度对材料离子电导率和电子电导率的影响,经8 h球磨和500℃烧结制备的LPSC在室温下具有最高的离/电子电导率比（2.091×10⁵）,其离子电导率高达4.049×10^-3 S·cm^-1,而电子电导率仅为1.936×10^-8 S·cm^-1。利用该电解质制备的712 NCM/LPSC/In-Li全固态电池在0.1 C的充放电倍率下首周放电比容量高达151.3 mAh·g^-1,且具有优良的循环稳定性。     

Preparation of Pt-PtOx thin films as electrode for memory capacitors

Pt-PtO_x thin films were prepared on Si(100) substrates at temperatures from 30 to 700°C by reactive r.f. magnetron sputtering with platinum target. Deposition atmosphere was varied with O₂/Ar flow ratio. The deposited films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. Resistively of the deposited films was measured by d.c. four probe method. The films mainly consisted of amorphous PtO and Pt₃O₄ (or Pt₂O₃) below 400°C, and amorphous Pt was increased in the film as a deposition temperature increased to 600°C. When deposition temperature was thoroughly increased, (111) oriented pure Pt films were formed at 700°C. Compounds included in the films strongly depended on substrate temperature rather than O₂/Ar flow ratio. Electrical resistivity of Pt-PtO_x films was measured to be from the order of 10⁻¹ Ω cm to 10⁻⁵ Ω cm, which was related to the amount of Pt phase included in the deposited films.     

结构化增韧层增韧RTM复合材料预成型体的渗透特性

选用尼龙无纺布(Polyamide Nonwoven Fabric,PNF)作为结构化增韧层,研究了增韧层的引入对纤维预成型体在树脂传递模塑成型(RTM)工艺过程中渗透特性的影响。结果表明:在径向非饱和流动模式下,层间增韧预成型体沿纤维方向的渗透率为5.2×10-12 m2,略低于非增韧预成型体的7.1×10-12 m2,而沿垂直于纤维方向的渗透率为2.3×10-12 m2,略高于非增韧预成型体的1.6×10-12 m2。此外,层间增韧预成型体的单向饱和流动渗透率为2.6×10-12 m2,较非增韧预成型体的1.9×10-11 m2下降了约1个数量级,z向饱和流动渗透率较非增韧预成型体的1.3×10-13 m2下降至2.5×10-14 m2,同样下降了约1个数量级。对复合材料层间微观形貌的分析结果表明:造成预成型体渗透率下降的主要原因首先是PNF引入至层间之后将阻碍层间树脂的快速流动,同时增韧层将使层内纤维含量明显升高,由55.3vol%上升到63.7vol%。     

纳米级Li4Ti5O12负极材料的制备及其输运特性

以酞酸丁酯和乙酸锂为前驱体,通过溶胶凝胶法成功制备了纳米钛酸锂Li_4Ti_5O₁₂(LTO)负极材料。采用X射线衍射分析、扫描电镜(SEM)和透射电镜(TEM)分别对材料的物相与形貌进行了表征分析,并研究了煅烧条件和包覆改性对LTO输运特性的影响。研究表明,煅烧温度为800℃,时间为10 h条件下制备的样品的输运特性最佳,离子电导率为8.8×10^-8 S/cm,电子电导率为8.53×10^-10 S/cm。均匀的碳包覆层可以有效地改善样品的输运特性,LTO/C复合活性材料的离子与电子电导率分别达到4.35×10^-7 S/cm和9.63×10^-8 S/cm。电化学性能测试表明,碳包覆后的活性材料在0.1 C倍率下首次放电容量可达172.4 mAh/g;在5 C高倍率下循环充放电50次后,容量保持率可达94.4%,表现出较好的电化学性能。     

Characterization of indium zinc oxide thin films prepared by pulsed laser deposition using a Zn3In2O6 target

Using a Zn₃In₂O₆ target, indium-zinc oxide films were prepared by pulsed laser deposition. The influence of the substrate deposition temperature and the oxygen pressure on the structure, optical and electrical properties were studied. Crystalline films are obtained for substrate temperatures above 200°C. At the optimum substrate deposition temperature of 500°C and the optimum oxygen pressure of 10⁻³ mbar, both conditions that indeed lead to the highest conductivity, Zn₃In₂O₆ films exhibit a transparency of 85% in the visible region and a conductivity of 1000 S/cm. Depositions carried out in oxygen and reducing gas, 93% Ar/7% H₂, result in large discrepancies between the target stoichiometry and the film composition. The Zn/In (at.%) ratio of 1.5 is only preserved for oxygen pressures of 10⁻²–10⁻³ mbar and a 93% Ar/7% H₂ pressure of 10⁻² mbar. The optical properties are basically not affected by the type of atmosphere used during the film deposition, unlike the conductivity which significantly increases from 80 to 1400 S/cm for a film deposited in 10⁻² mbar of O₂ and in 93% Ar/7% H₂, respectively.     

炭基体的结构对C/C复合材料导电性能的影响

采用CVI+PIC工艺制备以2D碳纤维预制体为增强体、由不同炭基体结构组成的C/C复合材料,随后在不同温度对其进行热处理得到不同石墨化度的炭基体结构,研究了PyC/ReC比值和石墨化度对材料电阻率的影响。结果表明,随着PyC/ReC比的提高低密度C/C复合材料的电阻率在27.3×10^-6~28.0×10^-6 Ω·m间基本不变,因为石墨微晶的尺寸和结构完整性的增大与材料孔隙率的提高对电阻的影响相反。随着PyC/ReC比的提高,高密度C/C复合材料的电阻率从24.9×10^-6 Ω·m降低到20.5 ×10^-6 Ω·m。其可能的原因是,材料内部的孔隙较少,孔隙率的轻微提高使阻碍载流子在导电网络中的有效传递的作用显著下降。随着热处理温度从1800℃提高到2500℃,C/C复合材料的石墨化度明显提高,电阻率明显降低,其主要原因是载流子浓度的提高和晶界散射的减弱。     

Anomalous elastic properties of RF-sputtered amorphous TeO2+x thin film for temperature-stable SAW device applications

The anomalous elastic properties of TeO_2+x thin films deposited by rf diode sputtering on substrates at room temperature have been studied. The deposited films are amorphous, and IR spectroscopy reveals the formation of Te-O bond. X-ray photoelectron spectroscopy confirms the variation in the stoichiometry of TeO_2+x film from x = 0 to 1 with an increase in the oxygen percentage in processing gas composition. The elastic parameters of the films in comparison to the reported values for TeO_2+x single crystal are found to be low. However, the temperature coefficients of elastic parameters of all deposited films exhibit anomalous behavior showing positive values for TC(C₁₁) in the range (32.0 to 600.0) x 10^-40 C^-1 and TC(C¹¹) = (35.0 to 645.5) x 10^-4degC^-1 against the negative values TC(Cn) = -2.7 x 10^-4degC^-1 and TC(C₁₁) = -0.73 x 10^-4degC^-1 reported for TeO₂ single crystal. The variation in the elastic parameters and their temperature coefficients is correlated with the change in the three-dimensional network of Te-O bonding. The anomalous elastic properties of the TeO_2+x films grown in 100% O₂ are useful for potential application in the design of temperature stable surface acoustic wave devices.     

Preparation of strontium titanate thin films by mirror-confinement-type electron cyclotron resonance plasma sputtering

Using mirror-confinement-type electron cyclotron resonance (ECR) plasma sputtering method, strontium titanate (SrTiO₃) thin films have been prepared on Si and Pt/Ti/SiO₂/Si substrates at a low substrate temperature (below 450 K) in a low pressure (2.7×10⁻² Pa) environment of pure Ar and Ar/O₂ mixture. Prepared film surfaces were very smooth regardless of high deposition rate (8.5 nm/min). The composition ratio Sr/Ti of Sr to Ti in the films varied with the distance between the target and the substrate. All as-deposited films on Si substrates were found to be amorphous and were crystallized by post-deposition annealing using an electric furnace at 650 K, i.e. approximately 250 K lower than annealing for films obtained by conventional RF magnetron sputtering. Post-deposition annealing of these films using millimeter-wave radiation decreased the crystallization temperature to a value of 550 K. Furthermore, all as-deposited films on Pt/Ti/SiO₂/Si substrates by a plasma of Ar and O₂ gas mixture were found to be crystallized regardless of no substrate heating.