The Preparation and Characterization of Small Mesopores in Siloxane‐Based Materials That Use Cyclodextrins as Templates

Porous thin films containing very small closed pores (～ 20 Å) with a low dielectric constant (～ 2.0) and excellent mechanical properties have been prepared using the mixture of cyclic silsesquioxane (CSSQ) and a new porogen, heptakis(2,3,6‐tri‐O‐methyl)‐β‐cyclodextrin (tCD). The pore sizes vary from 16.3 Å to 22.2 Å when the content of tCD in the coating mixture increases to 45 wt.‐% according to positronium annihilation lifetime spectroscopy (PALS) analysis. It has also been found that the pore percolation threshold (the onset of pore interconnectivity) occurs as the ～ 50 % tCD porogen load. The dielectric constants (k = 2.4 ～ 1.9) and refractive indices of these porous thin films decreased systematically as the amount of porogen loading increased in the coating mixture. The electrical properties and mechanical properties of such porous thin films were fairly good as interlayer dielectrics.     

Functionally Modified Macroporous Membrane Prepared by using Pulsed Laser Deposition

Pulsed laser deposition (PLD) is used to deposit pure metals (Pt and Au) and a mixture of metals (Pt–Ru) at the surface of a porous aluminum anodic oxide (AAO) substrate. In the case of Pt, thick films (> 300 nm) with pore diameters larger than 150 nm (macroporous), replicating the pore structure of the underlying AAO substrate, are obtained when PLD is performed at high (> 50 eV at^–1) kinetic energy (E_k) conditions. At lower E_k conditions, the characteristic structure of the AAO membrane is not discernable in the deposited film. In that case, the substrate is entirely covered by a film, the structure of which is not different from that of a Pt film deposited on a flat Si substrate under the same conditions. AAO membranes modified by macroporous Au and Pt–Ru alloy films are also prepared, demonstrating that the concept can be applied to a wide range of materials. The mechanisms responsible for the replication of the substrate pore structure in the metallic layer are discussed. These functionally modified macroporous membranes are electroactive and this aspect has been emphasized by studying the electrocatalytic properties of Pt and Pt–Ru modified macroporous membranes for CO oxidation.     

非制冷热释电薄膜红外探测器热绝缘结构的研制

采用由多孔 Si O2 薄膜和过渡 Si O2 薄膜组成的复合薄膜结构实现了非制冷热释电薄膜红外探测器的热绝缘 .利用溶胶凝胶方法制备了多孔 Si O2 薄膜以及过渡 Si O2 薄膜 ,通过优化制备工艺 ,使得多孔 Si O2 一次成膜厚度达到30 70 nm ,孔率达到 5 9% ;过渡 Si O2 一次成膜的厚度达到 1 88nm,孔率达到 4 % .AFM表明 ,由过渡 Si O2 薄膜与多孔Si O2 组成的复合薄膜结构的表面粗糙度远小于多孔 Si O2 薄膜的表面粗糙度 .该热绝缘结构有利于探测器后续各层功能薄膜的集成     

Synthesis and characterization of porous polymeric low dielectric constant films

This paper reports the synthesis and dielectric properties of a porous poly(arylether) material with an ultra-low dielectric constant for interlayer dielectric applications in microelectronics. The porous polymer films were successfully fabricated by a method of organic phase separation and evaporation. A dielectric constant k of 1.8 was achieved for a porous film with an estimated porosity of 40% and average pore size of 3 nm. Electrical and mechanical properties as well as coefficient of thermal expansion for both dense and porous polymer films were measured.     

脉冲激光沉积法制备氧化锌薄膜

ZnO是一种新型的Ⅱ-Ⅵ族半导体材料,具有优良的晶格、光学和电学性能,其显著的特点是在紫外波段存在受激发射。利用脉冲激光沉积法(PLD)在氧气氛中烧蚀锌靶制备了纳米晶氧化锌薄膜,衬底为石英玻璃,晶粒尺寸约为28-35 nm。X射线衍射(XRD)结果和光致发光(PL)光谱的测量表明,当衬底温度在100-250℃范围内时,所获得的ZnO薄膜具有c轴的择优取向,所有样品的强紫外发射中心均在378-385 nm范围内,深能级发射中心约518-558 nm,衬底温度为200℃时,得到了单一的紫外光发射(没有深能级发光)。这归因于其较高的结晶质量。     

铜薄膜内微孔对其力学性能影响及开裂行为研究

研究了铜薄膜内微孔对其力学性能影响及开裂行为,采用磁控溅射工艺制备聚酰亚胺柔性基板上铜薄膜,通过扫描电镜(SEM)对铜薄膜表面形貌表征、EDS能谱分析及SEM原位拉伸观察实验,得出磁控溅射工艺制备出超薄铜薄膜多为柱状晶结构,且带有微米级孔洞.并测得不同孔隙率铜薄膜载荷与位移增量的变化,由相关公式求出应力-应变关系;分析了不同孔径微孔的上下边缘沿晶开裂,微裂纹萌生、扩展的行为.结果表明:磁控溅射工艺在聚酰亚胺柔性基板上制备的微米级铜薄膜受拉伸时微孔沿晶开裂形成初始微裂纹,孔径≤4μm微孔处局部应力偏低,未能使微裂纹沿晶界改变方向继续扩展,微裂纹受到抑制;在较高的局部应力下,孔径>10μm微孔裂纹继续沿新的晶界方向扩展,与其他微孔裂纹连通;孔隙率越高,多孔微裂纹连通几率越高,薄膜力学性能就越差,且铜薄膜开裂可能性也越高.     

磁控溅射法制备的PZT非晶薄膜光学性质研究

采用磁控溅射方法在石英玻璃上制备了PbZrxTi1-xO3(PZT)(x=0．52)非晶薄膜,并测量了200～1100nm的紫外．可见．近红外透射光谱．基于薄膜的结构和多层结构的透射关系,发展了仅有6个拟合参数的光学常数计算模型．利用该模型,可以同时获得薄膜在宽波段范围内的光学常数和厚度,得到折射率的最大值为2．68,消光系数的最大值为0．562,拟合薄膜厚度为318．1nm．根据Tauc′s法则,得到PZT非晶薄膜的直接禁带宽度为3．75eV．最后,利用单电子振荡模型成功地解释了薄膜的折射率色散关系．     

Mechanical properties of a plasma-modified porous low-k material

For 45 nm and beyond microelectronics technology nodes, the integration of porous low dielectric constant (low-k) materials is now required to reach integrated dielectric constant values lower than 2.7. However, porous low-k materials have lower mechanical strength in comparison with traditional dense materials and are also affected by chemical diffusion through the interconnected porosity during the various integration processes. Different types of plasma post-treatments which lead to surface modification of the porous low-k material with possible formation of a top surface layer, change of surface structure and “pore sealing” effect were applied. Highly sensitive instruments for mechanical investigation of thin layers, such as the Ultra Nano Hardness Tester (UNHT) and Nano Scratch Tester (NST) were applied for characterization of the effect of the plasma post-treatments on the mechanical behavior of a porous low-k material. Preliminary results are presented and discussed in this paper.     

SnS薄膜的制备及其特性研究

以硫代乙酰胺、三乙醇胺、氯化亚锡和氨水作反应物,氯化铵作缓冲剂,采用化学浴法在玻璃衬底上沉积SnS薄膜。用XRD,SEM等手段分别对薄膜样品的晶体结构及表面形貌进行了表征。XRD分析结果表明薄膜样品为具有斜方晶体结构的多晶SnS薄膜,SEM测量结果显示薄膜晶粒尺寸为数十纳米。此外,本文还简要分析了氯化铵在反应中的作用。     

含有端基和碳桥结构的OSG薄膜性能研究

研究了具有甲基末端和碳桥结构的多孔有机硅酸盐玻璃(OSG)薄膜的化学组成、孔结构和力学性能。对薄膜进行不同的固化处理,形成稳定的多孔薄膜结构。结果表明,在空气环境中固化时,由于氧气的存在,碳桥形成硅醇的过氧化物自由基被破坏,薄膜的机械性能降低。尽管氮气固化样品中保留了乙烯桥接基团,空气固化样品的力学性能仍优于氮气固化样品。原因是空气固化中微孔的坍塌增加了薄膜内部密度,为硅醇基团的缩合创造了更有利的条件。     

Micro-mechanical testing of SiLK by nanoindentation and substrate curvature techniques

Advanced micro-mechanical characterization methods provide material properties of thin films for modeling thermo-mechanical behavior of thin films for micro-electronic applications. Here, we focus on the local measurement method of nanoindentation for finding visco-elastic properties, and a global method of substrate curvature testing that provides linear elastic properties. Our specimen SiLK, Dow chemicals, is a low-k dielectric thin polymer film with a thickness of 400 nm, 6 and 8 μm, deposited on Si substrate. Our results show temperature dependent linear elastic and linear visco-elastic material properties for thin film materials.     

ZnO薄膜的结构与光学性能研究

采用sol-gel法在石英衬底上制备了ZnO薄膜,通过改变溶胶浓度、涂敷层数及退火温度,研究了ZnO薄膜的形貌、结构性能及光学性能。结果表明,薄膜具有六方纤锌矿结构,表面均匀致密,晶粒大小在25～35nm之间,Zn含量为0.8mol/L的溶胶经旋涂并在500℃下退火1h后可获得最高的可见光透射率,平均透射率约为94%。获得的ZnO薄膜的光学带隙在3.27～3.29eV之间。     

Simulations of diffusion barrier deposition on porous low-k films

Implementation of Cu/low-k in advanced interconnections requires a diffusion barrier to prevent copper penetration in low-k dielectrics. The barrier should be continuous to prevent copper diffusion and thin enough to keep interconnection line resistance low. Deposition of a diffusion barrier becomes an issue when porous low-k dielectrics are used. We developed a Monte Carlo simulation model to describe deposition of a diffusion barrier on a porous low-k film. The model provided explanation for the sealing behavior of different porous film by TaN diffusion barrier. Previously we have shown that TaN barrier integrity depends on chemical nature of the substrate rather than on porous structure: the same barrier can be continuous on oxycarbide (SiOCH) but non-continuous on HSQ (hydrogen silsesquioxane) although porous structures of the two films are similar. Using the model, we show that surface diffusion of TaN during deposition plays a key role in continuous barrier formation. Presence of carbon suppresses TaN diffusion (probably by TaC formation) and the barrier does not penetrate deep into the film forming a continuous layer on the top surface. The model is also able to predict sealing behavior for different porous low-k films with different porosity/pore sizes.     

无机络合溶胶-凝胶法制备多孔ZnO薄膜

利用无机络合溶胶-凝胶法制备多孔ZnO薄膜,同时利用多种测试手段对薄膜的晶体结构、表面形貌、多孔和光学性能进行了研究.XRD和SEM的测试结果表明,ZnO薄膜的晶体结构为六方纤锌矿,薄膜表面呈多孔状.由孔径分布曲线得出薄膜的孔主要集中在介孔2.02nm和4.97nm;500℃煅烧得到的ZnO薄膜的比表面积是27.57m2/g;在不同温度下煅烧的薄膜在可见光区域透射率均高于85%,光学带宽为3.25eV.     

Porous low k film with multilayer structure used for promoting adhesion to SiCN cap barrier layer

For 28 nm technological node, porous ultra low dielectric constant (p-ULK) film has been used as an insulator in Cu interconnection in the back-end of the line (BEOL). The interfacial adhesion between p-ULK film and SiCN (nitrogen doping silicon carbon) cap barrier layer played the important role for the package, wiring bond, chip package interaction (CPI), peeling, and reliability. In this work, the thin initial oxide and thin transition films were deposited in situ before depositing p-ULK film, which was used for improving the interfacial adhesion between p-ULK film and SiCN film, The ULK film with multilayer structure was characterized by secondary ion mass spectroscopy (SIMS) for examining multilayer structure, focused ion beam (FIB) and transmission electron microscope (TEM) for observing interface, and four-point bending (4-PB) for testing interfacial adhesion. Results indicated that the interfacial adhesion was obviously improved by adding initial oxide and transition layer before the deposited p-ULK film, which hardly impact the capacitance using single layer structure.     

PET柔性衬底上生长绒面ZnO-TCO薄膜及其在薄膜太阳电池中的应用

利用低压金属有机化学气相沉积(LP-MOCVD)技术在PET柔性衬底上低温生长绒面结构ZnO-TCO薄膜,DEZn和H2O作为源材料,B2H6作为掺杂剂.详细研究了薄膜掺杂流量对ZnO薄膜微观结构以及光电性能影响.优化获得的PET/ZnO:B薄膜厚约为1 500nm时,绒面结构PET/ZnO薄膜的方块电阻约为10Ω,可...     

氧化锌薄膜的电化学沉积法制备及受激发射研究

采用一种简单的电化学沉积法，在三电极化学池中，以单一的硝酸锌水溶液作为电沉积液，制备了高光学质量的半导体ZnO薄膜。透射光谱测量表明其光学带隙为3．35eV，400～2000nm波段的光学透过率大于80％。X射线衍射(XRD)和原子力显微镜(AFM)研究表明，ZnO薄膜为纤锌矿结构的无序多晶颗粒膜，微晶尺寸小于250nm。当用355nm的皮秒脉冲激光作为抽运源垂直入射薄膜表面时，可以检测到400nm附近的近紫外受激发射光，其强度随入射强度呈超线性增长关系，阈值在196．8kW／cm^2处，并且激光发射是多模的和各个方向的，还与被激发的面积有关，表现为随机激光发射机制。     

Ti-Rich Barrier Layers Self-Formed on Porous Low-k Layers Using Cu(1?at.%?Ti) Alloy Films

To investigate the applicability of the technique of barrier self-formation using Cu(Ti) alloy films on porous low-k dielectric layers, Cu(1 at.% Ti) alloy films were deposited on porous SiOCH (low-k) dielectric layers in samples with and without ~6.5-nm-thick SiCN pore seals. Ti-rich barrier layers successfully self-formed on the porous low-k layer of both sample types after annealing in Ar for 2 h at 400°C to 600°C. The Ti-rich barrier layers consisted of amorphous Ti oxides and polycrystalline TiC for the samples without pore sealing, and amorphous TiN, TiC, and Ti oxides for the pore-sealed samples. The amorphous TiN originated from reaction of Ti atoms with the pore seal, and formed beneath the Cu alloy films. This may explain two peaks of Ti segregation at the interface that appeared in Rutherford backscattering spectroscopy (RBS) profiles, and suggests that the Ti-rich barrier layers self-formed by the reaction of Ti atoms with the pore seal and porous low-k layers separately. The total molar amount of Ti atoms segregated at the interface in the pore-sealed samples was larger than that in the samples without pore sealing, resulting in lower resistivity. On the other hand, resistivity of the Cu alloy films annealed on the porous low-k layers was lower than that annealed on the nonporous low-k layers. Coarser Cu columnar grains were observed in the Cu alloy films annealed on the porous low-k layers, although the molar amount of Ti atoms segregated at the interface was similar in both sample types after annealing. The cause could be faster reaction of the Ti atoms with the porous dielectric layers.     

Cu2SnS3薄膜的制备及性能研究

采用LBL(layer-by-layer)法制备了Cu2SnS3薄膜.即首先采用电化学方法在SnO2衬底上制备SnS薄膜,然后又在其上用化学沉积法制备CuS薄膜,最后进行退火处理得到厚度约为960 nm的Cu2SnS3薄膜.探讨了薄膜的制备机理、生长速度、结构和光学特性.制备的薄膜为多晶(Cu2SnS3)72z(三斜或假单斜晶系)结构,其直接光学带隙约为1.05 eV.     

退火温度对WO_3薄膜结构及气敏性能的影响

采用直流磁控溅射法制备了WO3薄膜,并在350~550℃时对薄膜进行退火处理,研究了退火温度对薄膜结构及气敏性能的影响。结果表明:退火前及350℃退火后的薄膜为非晶态,450℃和550℃退火后的薄膜为WO3–x型晶态;随退火温度的提高,薄膜厚度增加,晶粒度增大。550℃退火后薄膜的厚度,较450℃退火后薄膜厚30nm,晶粒度相差8nm;450℃和550℃退火后的薄膜,在150℃时对体积分数为0.05%的NO2的灵敏度接近于22。