溶液缩聚法制备聚酰亚胺绝缘膜及性能研究

以联苯四酸二酐(BPDA)和4,4’-二氨基二苯醚(ODA)为单体原料,利用溶液缩聚法制备聚酰亚胺(PI)绝缘膜,采用XRD、SEM、FT-IR对不同热亚胺化温度合成的PI薄膜结构和表面形貌进行了表征,利用超高阻微电流测试仪测试了热亚胺化温度和粉体含量对PI绝缘膜击穿场强的影响。结果表明,在真空度为1.0×10-2Pa条件下,300℃热亚胺化1h,聚酰亚胺酸(PAA)薄膜完全被热亚胺化,制备的PI绝缘膜内部结构致密;当BPDA和ODA的粉体含量为5%时,PI绝缘膜击穿场强高达2.15MV/cm,表明PI薄膜具有良好的电学性能。     

溶剂蒸汽辅助制备超薄PVP栅介质膜及性能研究

使用溶剂蒸汽辅助制备超薄PVP栅介质膜,得到了低漏电流密度(E=1 MV/cm时,为1.12×10-9A/cm2;E=2 MV/cm时,为5.42×10-9A/cm2)、膜厚为10 nm的超薄PVP栅介质膜,其单位面积栅电容达到了566 nF/cm2。此外,AFM测试表明溶剂蒸汽辅助退火使薄膜表面粗糙度由0.36 nm降到了0.21 nm,空间电荷限制电流法(SCLC)的分析结果表明薄膜体内陷阱密度减少了26%。     

DMCPS电子回旋共振等离子体沉积的SiCOH低介电常数薄膜结构及物性研究

本文采用电子回旋共振(ECR)等离子体技术和十甲基环五硅氧烷(DMCPS)源开展了SiCOH薄膜的研究工作,获得了介电常数为2.88的SiCOH低介电常数薄膜.薄膜经400℃热处理后,膜厚减小,最大相对变化率小于15%,呈现较好的热稳定性.薄膜在1MV/cm场强下的漏电流为8.9×10-6A/cm2,且场强达到2.5 MV/cm时,未发生击穿现象,具有较优越的绝缘性能.因此,采用ECR-CVD技术和DMCPS源可以制备热稳定性优良的、绝缘性能优越的低介电常数SiCOH薄膜.     

热和化学亚胺化对ODPA/ODA聚酰亚胺薄膜性能的影响

以4,4'-二胺基二苯醚(ODA)和3,3',4,4'-二苯醚四酸二酐(ODPA)为单体,采用两步法,分别经热亚胺化和化学亚胺化过程制备了两种聚酰亚胺(PI)薄膜,并对两种薄膜的性能进行了表征.傅立叶红外光谱(FT-IR)表明两种薄膜均已完全亚胺化.化学亚胺化的PI薄膜的玻璃化温度、热稳定性均高于热亚胺化的薄膜.拉伸性能测试表明热亚胺化的薄膜具有较高的断裂伸长率,而化学亚胺化的薄膜的拉伸强度、弹性模量较大.     

SiO2/聚酰亚胺/SiO2复合薄膜绝缘性能及基于聚酰亚胺复合薄膜的后栅型场致发射性能的研究

使用射频磁控溅射和化学溶液法制备了SiO2/聚酰亚胺(PI)/SiO2绝缘膜。分别使用X射线衍射、扫描电镜对薄膜结构和薄膜表面形貌进行了表征;利用超高阻微电流测试仪测试了SiO2/PI/SiO2复合绝缘膜漏电流和电压击穿特性;采用SiO2/PI/SiO2作为绝缘膜,制作了后栅型场致发射器件,使用场发射测试系统测试了器件的开启电压、发射电流以及发光亮度。结果表明:SiO2/PI/SiO2复合绝缘膜具有高的击穿电压和低的漏电流密度,后栅器件中栅极对阴极表面的电场强度调控作用明显,阳极电压为750V时,栅极开启电压为91 V,阳极电流可达384μA,栅极漏电流仅为59μA,器件最高亮度可达600 cd/m2。     

PMMA分子量对其电学特性的影响

通过分析以PMMA[poly(methyl methacrylate)]为绝缘膜的MIS结构的电学特性,研究了分子量对PMMA薄膜电学特性的影响。PMMA薄膜通过旋涂溶于氯仿的20mg/ml PMMA溶液制成。PMMA薄膜厚度为220nm,临界电场超过1.8MV/cm。测量结果表明:(1)996K分子量PMMA薄膜的单位面积漏电流最小,仅有6.0×10-9/cm2。350K分子量的漏电流较大,为8.5×10-9/cm2;(2)高电场下决定漏电流与场强关系的物理机制是肖特基发射,通过线性拟合计算出银电极与PMMA之间的势垒高度约为0.5eV;(3)分子量大的PMMA陷阱密度小。996K分子的最小,为4.7×1010/cm2。     

溶胶-凝胶法制备聚酰亚胺/SiO2杂化薄膜及性能研究

以正硅酸四乙酯(TEOS)为硅源,4,4′-(六氟异丙烯)二酸酐(6FDA)为二酐单体,4,4′-二氨基二苯醚(ODA)为二胺单体,采用无水溶胶-凝胶法制备聚酰亚胺(PI)/二氧化硅(SiO_2)杂化薄膜(PI-SiO_2)。将3-氨基丙基三甲氧基硅烷(APS)通过化学键合连接到PI分子链上,使SiO_2颗粒在PI基体中均匀分散。研究了PI-SiO_2杂化薄膜的光学性能和热学性能。随着SiO_2含量的增加,PI-SiO_2杂化薄膜的黄色指数明显降低。在SiO_2添加量为40%(wt,质量分数)条件下,制得的PI-SiO_2的玻璃化转变温度最高为314.7℃,热膨胀系数(CTE)为27.65×10-6/℃,具有较好的热性能。     

新型纳米ZrO2/聚酰亚胺复合超薄膜的制备表征及其介电性能

以油酸为有机配体,采用两相方法合成了油溶性的超小尺寸纳米晶体纳米ZrO₂（nano ZrO₂）,并对nano ZrO₂表面包覆的油酸改性使纳米晶体与聚酰胺酸（PAA）接枝,通过旋膜法热亚胺化后形成nano ZrO₂/聚酰亚胺（PI）复合超薄膜。利用TEM、XRD、FTIR和SEM等对nano ZrO₂及nano ZrO₂/PI复合超薄膜进行表征,并对nano ZrO₂/PI复合超薄膜的介电性能进行了探究。结果显示,nano ZrO₂尺寸均一（5.0 nm左右）,为锐钛矿晶型,其晶体结构和尺寸不受改性接枝影响。nano ZrO₂在复合超薄膜中分散良好。电学研究表明,复合超薄膜的介电性能受nano ZrO₂与PAA质量比及制膜热亚胺化温度的影响。当PAA∶ZrO₂质量比为2∶3、热亚胺化温度为320℃时,介电常数达到最大,几乎是纯PI薄膜的2倍。两相法-改性接枝-热亚胺化制备PI复合超薄膜的方法简单高效,能够避免无机粒子在PI基体内的团聚并提高介电性能,对于PI基复合薄膜的制备、应用及推广具有重要意义。     

一种可溶性聚酰亚胺的合成及亚胺化研究

选用双酚-A二醚二酐(BPADA)和4,4’-二胺基二苯醚(ODA)为单体,间-甲酚为溶剂,用化学亚胺化法合成高分子量可溶性的聚酰亚胺(PI),得到的PI在极性溶剂NMP、DMAc、THF和DMF中有很好的溶解性。通过FT-IR和GPC对PI的结构和化学亚胺化过程中分子量变化进行研究,并利用DMTA对化学亚胺化和热亚胺化PI的性能进行表征。结果表明,化学亚胺化得到的PI具有很高的亚胺化程度,与热亚胺化PI具有相同的玻璃化转变温度;但由于形成了分子链间的交联,热亚胺化PI不能被溶解,且模量比化学亚胺化PI高。     

直接法聚酰亚胺覆铜箔的制备EI北大核心CSCD

以2,2′-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)、对苯二胺(PDA)和4,4’-联苯四甲酸二酐(BPDA)为原料,采用共聚法合成了聚酰胺酸(PAA)树脂;然后将PAA树脂涂布到电解铜箔表面上,在高纯氮气保护下进行热亚胺化处理,最后制备出一种表观平整、光滑的聚酰亚胺(PI)覆铜箔。研究了BAPP/PDA物质的量比、PAA树脂的预固化工艺和热亚胺化工艺以及收卷牵引力对PI性能的影响。结果表明,BAPP/PDA物质的量比为1.5/4.5,PAA树脂预固化时涂布速度为0.6m/min、烘道长度为9m、烘道温度分布为110℃、140、170℃,PAA树脂热亚胺化工艺为200℃/1h、250℃/1h、320℃/2h和收卷牵引力为14kg^16kg时,所制备的PI覆铜箔性能较佳。     

SPPEK/PWA质子导电复合膜的制备与性能

以磺化杂萘联苯聚醚酮(SPPEK)为基体,采用共混法制备了SPPEK/PWA复合质子交换膜。采用红外光谱、热分析与交流阻抗等方法对复合膜的结构和性能进行了研究,并与Nafion117膜进行了比较。结果表明,磷钨酸(PWA)的掺杂使得复合膜的吸水率和溶胀度增大,同时热稳定性能得到提高。复合膜在20℃时的质子电导率为0.67×10-2S/cm,接近Nafion117膜的质子电导率(1.08×10-2S/cm)。且随着温度的升高,电导率逐渐增大,最高可达1.18×10-2S/cm。此外,对复合膜不同方向上的电导率进行了测试,表明膜平面方向上的电导率(8.10×10-2S/cm)高于厚度方向上电导率(7.50×10-3S/cm)约一个数量级。     

A comparative study of low dielectric constant barrier layer, etch stop and hardmask films of hydrogenated amorphous Si-(C, O, N)

New barrier layer, etch stop and hardmask films, including hydrogenated amorphous a-SiC_x:H (SiC), a-SiC_xO_y:H (SiCO), and a-SiC_xN_y:H (SiCN) films with a dielectric constant (k) approximately 4.3, are produced using the plasma-enhanced chemical vapor deposition technique. The chemical and structural nature, and mechanical properties of these films are characterized using X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and nano-indentation. The leakage current density and breakdown electric field are investigated by a mercury probe on a metal-insulator-semiconductor structure. The properties of the studied films indicate that they are potential candidates as barrier layer, etch stop and hardmask films for the advanced interconnect technology. The SiC film shows a high leakage current density (1.3×10⁻⁷ A/cm² at 1.0 MV/cm) and low breakdown field (1.2 MV/cm at 1.0×10⁻⁶ A/cm²). Considering the mechanical and electrical properties requirements of the interconnect process, SiCN might be a good choice, but the N content may result in via poison problem. The low leakage current (1.2×10⁻⁹ A/cm² at 1.0 MV/cm), high breakdown field (3.1 MV/cm at 1.0×10⁻⁶ A/cm²), and relative high hardness (5.7 GPa) of the SiCO film indicates a good candidate as a barrier layer, etch stop, or hardmask.     

SnP2O7中温固体电解质的制备和导电性能

用固相反应法制备了不同P/Sn物质的量比的SnP2O7,并研究了该电解质在120～260℃范围内的导电性能。XRD分析表明SnP2O7为立方结构。热重分析了电解质在中温范围内的稳定性。用交流阻抗谱测量了电解质电导率,电导率随着HPO3在电解质中的残余量的提高而提高。测试结果表明电解质中起导电作用的主要是HPO3,而SnP2O7主要起支撑作用。最大电导率是在200℃,P/Sn物质的量比为3.0时,干空气条件下为5.1×10-2S/cm,湿空气条件下为6.6×10-2S/cm。     

Comparative Study of LiMn2O4 Thin Films Heat-treated by Conventional and Rapid Thermal Annealing

Cathode material LiMn2O4 thin films were prepared by solution deposition followed by conventional thermal annealing (CTA) and rapid thermal annealing (RTA) using lithium acetate and manganese acetate as starting materials. The phase and surface morphology identification was done by X-ray diffraction and scanning electron microscopy. The electrochemical properties of the thin films were carried out by cyclic voltammetry, charge-discharge experiments, electrochemical impedance spectroscopy and potential step technique. The results show that both thin films are homogeneous and crack-free. Compared with the CTA derived thin films, the RTA derived ones with smaller grain size are more smooth and dense. The CTA and RTA derived LiMn2O4 thin films deliver the capacity of 34.5 μAh/(cm2 ·μm) and 38 μAh/(cm2 ·μm) and show the capacity loss of 0.050% and 0.037% per cycle after being cycled 100 times, respectively. The diffusion coefficient of lithium ion in the CTA derived LiMn2O4 thin-film electrode is 4.59×10-11 cm2/s, and that of lithium ion in the RTA derived one is 3.86×10-11 cm2/s.     

Effects of Substrate Temperature on Properties for Transparent Conducting ZnO:A1 Films on Organic Substrate Deposited by r.f. Sputtering

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Environmentally stable flexible metal-insulator-metal capacitors using zirconium-silicate and hafnium-silicate thin film composite materials as gate dielectrics

Fully flexible metal-insulator-metal (MIM) capacitors fabricated on 25 microm thin polyimide (PI) substrates via the surface sol-gel process using 10-nm-thick zirconium-silicate (ZrSixOy) and hafnium-silicate (HfSimOn) films as gate dielectrics. The surface morphology of the ZrSixOy and HfSimOn films were investigated using atomic force microscopy and scanning electron microscopy, which confirmed that continuous and crack-free surface growth had occurred on the PI. Both the films treated with oxygen (O2) plasma and annealing (ca. 250 degrees C) consisted of amorphous phase; confirmed by X-ray diffraction. We employed X-ray photoelectron spectroscopy (XPS) at high resolution to examine the chemical composition of the films subjected to various treatment conditions. The shift of the XPS peaks towards higher binding energy revealed the O2 plasma-pretreatment followed by annealing was the most effective process to the surface oxidation at relatively low-temperature, for further passivate the grease traps and making dielectric films thermally stable. The ZrSixOy and HfSimOn films in sandwich-like MIM configuration on the PI substrates exhibited the low leakage current densities of 7.1 x 10(-9) and 8.4 x 10(-9) A/cm2 at applied electric field of 10 MV/cm and maximum capacitance densities of 7.5 and 5.3 fF/microm2 at 1 MHz, respectively. In addition, the ZrSixOy and HfSimOn films in MIM capacitors showed the estimated dielectric constants of 8.2 and 6.0, respectively. Prior to use of flexible MIM capacitors in advanced flexible electronic devices; the reliability test was studied by applying day-dependent leakage current density measurements up to 30 days. These films of silicate-surfactant mesostructured materials have special interest to be used as gate dielectrics in future for flexible metal-oxide-semiconductor devices.     

高离子传导纳米多孔β-Li3PS4固态电解质的湿化学法制备

利用湿化学法,并采取逐步加热脱除沉淀中四氢呋喃分子的方式,制备具有高离子电导率和低活化能的纳米多孔β-Li 3PS 4固态电解质。利用同步热分析、X射线衍射、扫描电镜、拉曼光谱、氮气吸脱附和交流阻抗测试等手段研究不同处理阶段产物的形貌、结构和物相组成,并测试分析β-Li 3PS 4固态电解质的电化学性能。结果表明:采用该方法制备的纳米多孔β-Li 3PS 4固态电解质比表面积为 28.3m 2·g -1 ,平均孔径约23nm,电化学测试表明该电解质在20℃下的离子电导率为1.84×10 -4 S·cm -1 ,活化能为0.343eV,电子电导率为1.3×10 -8 S·cm -1 ,具有优异的电化学稳定性,与金属锂负极也具有良好的兼容性。     

室温下高速沉积AZO薄膜的研究

在室温下,采用射频磁控溅射技术以较大的功率密度(7W/cm2)沉积了一系列掺铝氧化锌(AZO)透明导电薄膜,探索了溅射压强对沉积速率及薄膜性能的影响。结果表明,当工作压强为2.0Pa时,高速(67nm/min)沉积得到的薄膜的电阻率为2.63×10-3Ω.cm,可见光平均透过率为83%,并且在薄膜表面有一定的织构。     

在金属基片上以LNO为过渡层制备Pb(Zr0.53Ti0.47)O3薄膜的电性能

采用溶胶-凝胶法和快速热处理工艺,分别以不锈钢(SS)和镍合金(NC)为基片,成功制备了表面均匀、无裂纹的锆钛酸铅(Pb(Zn0.53Ti0.47)O3,简写为PZT)薄膜.为了缓解金属基片与PZT薄膜之间由于晶格常数和热膨胀系数不同所造成的不匹配状态,引入了镍酸镧(LaNiO3,简写为LNO)薄膜作为过渡层.XRD和SEM结果表明,经过600℃下30min的晶化,PZT薄膜已经由无定型转化为钙钛矿相.以LNO为过渡层,在NC金属基片上制备的PZT薄膜具有较高的介电常数和较低的损耗(1kHz下ε=717,tanδ=0.08),较低的漏电流(50kV/cm下J=2.6×10-7A/cm2)以及较好的铁电性能(+Pr=90μC/cm2,-Pr=14 μC/cm2,Ec=32.5kV/cm).同时,在SS基片上,通过引入LNO过渡层,制备的PZT薄膜也具有比较好的性能.