溅射Ta薄膜的内应力

本文应用磁控直流溅射方式制备厚度从０．１μｍ～０．２５μｍ的Ｔａ薄膜，通过改变溅射功率、基片的交流偏压和不同的基片，测定Ｔａ薄膜的内应力。研究结果表明：在通常的溅射条件下，Ｔａ溅射膜的内应力为压应力；随着溅射功率的提高，其内应力逐步增大；当基片偏压升高，内应力也呈上升的趋势，但其对内应力的影响大于溅射功率的改变。不同的基片对Ｔａ膜内应力的大小也有一定的影响。     

ITO薄膜的制备及其光电特性研究

采用直流磁控溅射法,分别用ITO陶瓷靶、In-Sn合金靶,在玻璃基片上镀膜。研究ITO透明导电膜其膜厚、靶材、溅射气压和溅射速率等工艺对光电特性的影响。结果表明,采用陶瓷靶镀膜要比合金靶效果好,膜厚70nm以上、溅射气压0.45Pa和溅射速率23nm/min左右为最佳工艺条件,并得到了ITO薄膜电阻率1.8×10–4Ω.cm、可见光透过率80%以上。     

不同沉积工艺参数对YF3膜层应力的影响

薄膜材料的选择及其膜层特性的研究,是光学薄膜技术的基础和前提.YF3硬度较高,折射率较低,是优选的红外低折射率材料,但存在成膜后膜层的应力较大的缺陷.通过研究镀膜过程中基片的烘烤温度、辅助离子源能量以及成膜后的热处理条件对YF3膜层应力的影响,分析了YF3膜层的应力随所选定工艺参数的变化规律.     

沉积温度对电子束蒸发HfO2薄膜残余应力的影响

采用电子束蒸发沉积方法在BK7玻璃基底和熔融石英基底上沉积了HfO2薄膜,研究了不同沉积温度下的应力变化规律。利用ZYGO干涉仪测量了基片镀膜前后曲率半径的变化,计算了薄膜应力。结果发现在所考察的实验条件下HfO2薄膜的残余应力均为张应力,应力值随沉积温度的升高先增大后减小。两种基底上薄膜的残余应力的主要产生机制不同。对于BK7玻璃基底HfO2薄膜的残余应力起决定作用的是内应力,熔融石英基底上HfO2薄膜的残余应力在较低沉积温度下制备的薄膜起决定作用的是热应力,在沉积温度进一步升高后内应力开始起决定作用。通过对样品的X射线衍射(XRD)测试,发现在所考察的温度范围内,HfO2薄膜的结构发生了晶态转换,这一结构转变与薄膜残余应力的变化相对应。两种基底上薄膜微结构的演变及基底性能差异是两种基底上薄膜应力不同的主要原因。     

金属膜对单介质板太赫兹波导传输特性的影响

理论分析了对称金属薄膜镀层对厚单介质板太赫兹波导TM模传输特性的影响,发现镀膜前后TM模损耗相差巨大,并且随太赫兹频率的增加TM模损耗差异会更大。对低损耗厚单介质板,金属膜对TM模损耗的影响不可忽视。进一步研究了镀膜对TM模模场分布的影响,发现镀膜前后厚单介质板内TM模模场分布显著不同。     

金属与导电材料

0019789NiCr 溅射薄膜内应力的研究[刊]/于映//真空电子技术.-2000,(5).-9～12(C)本文采用磁控溅射法在0.5mm 厚的40Cr 钢基片上沉积1～12μm 的 NiCr 合金薄膜,运用钠光平面干涉法测量 NiCr 溅射薄膜的内应力,研究表明影响NiCr 薄膜内应力的主要因素是工作气压和基片温度,并运用 Klokolm 理论对该影响作用进行了分析。参5     

退火温度对铝互连线热应力的影响

采用二维面探测器X射线衍射(XRD)测量1μm和0.5μm厚Al互连线退火前后的残余应力.沉积态Al线均为拉应力,且随膜厚的增加而减小.沿长度方向的应力明显高于宽度方向的应力,表面法线方向应力最小.250℃退火2.5h后,互连线在各方向上的应力都减弱,其中1μm Al线应力减弱幅度高于0.5μm互连线.采用电子背散射衍射(EBSD)方法,测量退火前后Al互连线(111),(100),(110)取向晶粒的IQ值.退火后平均IQ值提高,互连线残余内应力随之减小.EBSD分析结果与XRD应力测试结果相符合.     

退火温度对铝互连线热应力的影响

采用二维面探测器X射线衍射(XRD)测量1μm和0.5μm厚Al互连线退火前后的残余应力.沉积态Al线均为拉应力,且随膜厚的增加而减小.沿长度方向的应力明显高于宽度方向的应力,表面法线方向应力最小.250℃退火2.5h后,互连线在各方向上的应力都减弱,其中1μm Al线应力减弱幅度高于0.5μm互连线.采用电子背散射衍射(EBSD)方法,测量退火前后Al互连线(111),(100),(110)取向晶粒的IQ值.退火后平均IQ值提高,互连线残余内应力随之减小.EBSD分析结果与XRD应力测试结果相符合.     

非电量测量与设备

0215967脉冲离子源所镀膜层厚度分布曲线的测量〔刊)/蔡长龙刀真空电子技术一2002,(2)一25一27(C) 为了解决大面积类金刚石薄膜的均匀性,首先要研究脉冲离子源所镀制的类金刚石薄膜的厚度分布曲线。针对这一目的,做了大量工艺实验,在不同的脉冲离子源电源参数(主回路电压,脉冲频率)、基片高度以及磁场等工艺参数下制备了样品,并选择了一种合适的膜厚测量仪器进行了膜厚分布测量,获得了在各种工艺参数下脉冲离子源所镀膜层厚度的分布曲线。参 0215968数字式温度计DS18B20的特性及应用〔刊)/陈兴梧//国外电子元器件一2002,(3)一39一41(C) 02…     

金刚石厚膜热残余应力三维模拟及失效分析

运用ANSYS软件建立了三维轴对称有限元模型,对金刚石厚膜(φ40mm×1mm)内部和膜/钼基体界面处的热残余应力各个分量的分布作了全面的模拟,讨论了热残余应力对金刚石厚膜失效的影响.结果表明,金刚石厚膜内的热残余应力各个分量并非均匀分布,离界面越近,其值越大;界面处大的轴向拉应力和剪应力对于厚膜从基体上脱落有重要影响;在膜的上表面靠近外边缘局部区域内存在较大的径向拉应力和轴向拉应力,是造成膜开裂失效的原因;本文的三维有限元模型比以往的一维解析模型更全面,且能更合理地解释金刚石膜的失效现象.     

Non-destructive evaluation of residual stresses in thin films via x-ray diffraction topography methods

Quantitative x-ray diffraction topography techniques have been used to measure the residual strain magnitude and uniformity of deposition for Mo and W sputtered films on Si(100) substrates. High sensitivity rocking curve measurements were able to determine differential strains for films as thin as 2.5 nm; while Bragg angle contour mapping had similar sensitivity and was also able to assess coating uniformity and stress distribution over areas covering a whole wafer. Measurements of strain versus film thickness over a range of 2.5 nm to 80 nm showed that a critical thickness exists for maximum residual strain. Growth beyond this range produces stress relaxation. This non-destructive type of analysis could be employed on a wide range of film-substrate combinations.     

激光熔蚀反应淀积AlN薄膜残余应力及热稳定性的研究

激光熔蚀反应淀积于 Si(10 0 ) ,Si(111)基底上的 Al N薄膜是高质量高取向性的 Al N多晶膜 ,薄膜与基底的取向关系为 Al N(10 0 )∥ Si(10 0 ) ,Al N(110 )∥ Si(111)。薄膜具有较低的残余应力和较好的热稳定性。实验结果表明 ,当氮气压强和放电电压分别为 10 0× 133.33Pa和 6 50 V时 ,薄膜的残余应力低于 3GPa。此样品在纯氧环境 50 0℃时 ,经过 3h的退火 ,红外吸收谱检测未发现有Al2 O3 特征峰出现。对 Al N/Cu双层膜的研究表明所制备的 Al N薄膜在金属薄膜的防护上也有潜在的应用价值。     

脉冲激光沉积法制备的PZT铁电薄膜的残余应力

根据压电本构方程和细观力学统计平均法，采用X射线衍射（XRD）测量Pb（Zr0.52Ti0.48）O5（PZT）铁电薄膜的残余应力。考虑激光沉积生长过程中，薄膜相变应力、热应力和本征应力对自由能的贡献，分析薄膜晶胞在晶体坐标系上的应力应变状态。由坐标转换将晶胞残余应力从晶体坐标系转换到样品坐标系得到任意取向晶粒的残余应力，通过取向平均得到薄膜样品坐标系上的残余应力。用脉冲激光沉积法（PLD）制备了不同厚度的PZT薄膜。利用X射线衍射分别采用细观力学统计平均法和传统sin^2φ法测量了PZT薄膜的残余应力。结果表明，两种结果在数值上是比较接近的（绝对差范围0．3～16．6MPa），残余压应力随着膜厚的增加从96MPa左右减少到45MPa左右。最后讨论了细观力学统计平均法的优缺点。     

不同厚度PZT薄膜的制备及电性能特性研究

采用sol-gel（溶胶-凝胶）法在Pt/Ti/SiO2/Si基底上分别制备了厚度为400nm,600nm,800nm的PZT（锆钛酸铅,Zr/Ti=52/48）薄膜,研究了厚度对薄膜介电性能与铁电性能的影响。通过对薄膜的铁电性能与介电性能进行测试,分析了不同厚度薄膜的剩余极化强度、介电常数与介电损耗;通过对介电调谐率与最大正切损耗的计算,进一步分析了薄膜的介电调谐性能。实验结果表明,薄膜的介电常数与介电损耗随薄膜厚度的增大而增加;厚度为600nm的薄膜具有最好的介电调谐性能与铁电性能。     

射频磁控溅射法制备掺锆氧化锌透明导电薄膜

利用射频磁控溅射法在室温下制备出了掺锆氧化锌(ZnO∶Zr)透明导电薄膜。研究了溅射压强对ZnO∶Zr薄膜表面形貌、结构、光学和电学性能的影响。结果表明:ZnO∶Zr薄膜为六角纤锌矿结构的多晶薄膜,且具有c轴择优取向,溅射压强对薄膜电阻率有显著影响,压强为1.5Pa时,电阻率具有最小值1.77×10–3Ω·cm。所制备的ZnO∶Zr薄膜具有良好的附着性能,在可见光区平均透过率超过93%。     

基于纳米胺结构保护层的多波段高反射Ag基膜系制备

Ag基膜系具有在可见到近红外波段最高的反射率,但Ag的环境稳定性较差,易受腐蚀而导致反射率降低。采用离子束辅助电子束蒸发沉积(IAD)方式制备了不同厚度比例的Ta₂O₅-SiO₂纳米胺薄膜,计算出有效折射率和膜层残余应力,选用Ta₂O₅厚度占比为75%的纳米胺薄膜,进一步设计制备了纳米胺结构保护层Ag基膜系和常规两层式结构保护层Ag基膜系,实现了多波段高反射率目标,并且两种Ag基膜系的残余应力相近。在24 h湿热实验后,纳米胺结构保护层Ag基膜系的反射率红移量小于常规两层式结构保护层Ag基膜系;在144 h湿热实验后,纳米胺结构保护层Ag基膜系表面缺陷腐蚀程度小于常规两层式结构保护层Ag基膜系,结合聚焦离子束制样后利用TEM观察结果,表明纳米胺结构保护层具有更高的致密度,能够为Ag基膜系提供更优良的环境稳定性。     

A study of residual stress distribution through the thickness of p+ silicon films [thermal oxidation effects]

The effect of thermal oxidation on the residual stress distribution throughout the thickness of heavily-boron-doped (p⁺ ) silicon films is studied. The deflection of p⁺ silicon cantilever beams due to residual stress variation throughout the film thickness is studied for as-diffused and thermally oxidized films. Cantilevers of as-diffused p⁺ silicon films display a positive curvature (or a negative bending moment), signified by bending up of the beams. Thermal oxidation of the films prior to cantilever fabrication by anisotropic etching modifies the residual stresses in the p⁺ film, specially in the near-surface region (i.e. the top 0.3 to 0.5 μm for the oxidation times used here), and can result in beams with a negative curvature even when the oxide is removed from the p⁺ silicon cantilever surface subsequent to cantilever fabrication     

Stress development during evaporation of Cu and Ag on silicon

This work presents results of stress measurements during deposition of thin silver and copper films on 100 μm Si substrate. The stress in thin films has been determined by means of an optical system for the measurement of sample’s curvature. This system was applied in situ in a high vacuum deposition system. For Ag films the stress occurring during deposition goes from a low compressive value to tensile for thickness less than 30 nm and to compressive above this. For Cu films we observe tensile stress for thickness less 20 nm and above 50 nm. The same general trend of stress evolution with thickness is present in all cases at initial stage. There is the same growth mode for Cu and Ag because of the similar shapes of stress curves for thickness lower than 30 nm The behavior of stress evolution was explained by island nucleation and growth, island coalescence and continuous film growth. The difference in the stress evolution above 30 nm is caused by the fact that silver may be less sensitive than copper to adsorption of impurities. Adsorbed contamination inhibits compressive stress increase generated by grain boundary and defects remaining in the film.     

Diffusional creep induced stress relaxation in thin Cu films on silicon

The results of stress measurements during annealing of thin copper films deposited on 100 μm Si substrates are presented. The stress in thin films was determined by using an optical system for curvature measurements. The annealing experiments were done during thermal cycles of heating and cooling procedures from room temperature up to 400 °C with a rate 10 °C/min. The total thickness of thin films was between 20 and 100 nm. The obtained results showed that the difference between the end and the initial values of the ratio of force to width increases with the thickness of the samples. The initial linear shape of the temperature-stress plots reaches higher temperature values with an increase in film thickness. In order to explain the observations, the dependence of stress on temperature was calculated using the rate of Coble creep. It was found that the theoretical curves reveal the same features as the experimental data. It was concluded that diffusional creep mechanism dominates for thin film of thickness below 100 nm.     

沉积功率和气压对低频氮化硅薄膜应力的影响

利用等离子体增强化学气相沉积(PECVD)工艺,在不同射频功率,不同反应气压条件下制备了氮化硅薄膜。研究了低频工艺中氮化硅薄膜的沉积速率、应力以及厚度均匀性与其二者的关系。结果表明,射频功率的改变直接影响到离子对衬底的轰击效应,而反应气压的改变影响气体分子的平均自由程。离子轰击效应和分子平均自由程对氮化硅薄膜的生长过程产生影响,从而影响沉积速率、应力以及厚度均匀性等基本性质。