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实验研究了不同激光预处理参数对于纳秒激光多脉冲作用下HfO2/SiO2反射膜损伤形态转化的影响。通过对比两类损伤扩张性和对薄膜功能性破坏机制,提出激光预处理技术的重要意义在于抑制损伤形态转化过程。通过薄膜损伤形态分析揭示了激光预处理作用机制为节瘤缺陷的去除和亚表面吸收前驱体的形成两方面的综合作用。实验结果表明:预处理后薄膜损伤形态转化特征曲线向更高通量和更多发次方向平移。针对现有工艺下的薄膜,采用高通量、两台阶的预处理参数组合能够获得兼顾效率的最佳收益,其零几率损伤形态转化阈值最高可以提升140%。 相似文献
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利用小口径元件损伤测试平台对HfO2/SiO2高反膜的1 064 nm激光多脉冲损伤规律进行了研究。研究结果表明:多脉冲作用下HfO2/SiO2高反膜损伤在形态上主要分为色斑和层裂两类,在一定条件的多发次脉冲作用下,色斑损伤存在向层裂损伤转换的趋势;层裂损伤尺寸随脉冲发次呈指数递增后趋于极大值的变化规律,且终态尺寸与辐照激光能量密度呈近似线性关系;色斑S-on-1损伤阈值与脉冲发次关系不明显,而层裂S-on-1损伤阈值随脉冲发次增加呈指数衰减后趋于极小值的变化规律。采用衰减公式拟合手段,对元件抗损伤能力退化规律进行了初步的定量分析。 相似文献
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以获得高去除速率和低表面粗糙度为目标,建立了基于纳米氧化铈-硅溶胶复配混合磨料新模式。采用小粒径、低分散度的30 nm氧化铈-硅溶胶复配混合作为磨料,利用氧化铈对硅片表面化学反应产物硅酸胺盐的强络合作用,加快了硅衬底表面化学反应进程。分析了复合磨料抛光的机理,通过Aglient 5600LS原子力显微镜,测试了抛光前后的厚度及抛光后的硅片表面微粗糙度。实验结果表明,复合磨料抛光后硅片表面在10μm×10μm范围内粗糙度方均根值0.361 nm,表面微粗糙度降低16%以上,去除率为1 680 nm/min,硅CMP速率提高8%以上,实现了高去除速率、低表面粗糙度的硅单晶抛光。 相似文献
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脉冲激光沉积TiN/AlN多层膜的微结构与力学性能 总被引:1,自引:1,他引:0
采用脉冲激光沉积(LPA)法,在单晶Si表面制备了调制周期为50nm的不同调制比的TiN/AlN多层膜,并研究了调制比对多层膜微结构和力学性能的影响。扫描电镜(SEM)和原子力显微镜(AFM)显示,薄膜的调制比在1~4之间。并且小调制比下薄膜表面的岛密度小,岛面积过大,分布不均匀,相邻岛之间的起伏较大。X射线衍射(XRD)结果表明,小调制比下,AlN相为明显的(002)择优取向,TiN相主要以(200)、(220)形式存在;调制比增大后,AlN相的择优取向减弱,同时伴随着薄膜晶粒的细化及硬度增强,这一研究结果说明,调制比对多层膜的性质有一定的影响,大调制比会导致Al元素在界面处聚集,并与TiN进行合金化后的形成TiAlN结构,进而对薄膜的硬度产生影响。 相似文献
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为了在浅沟槽隔离(STI)化学机械平坦化(CMP)过程中提高对SiO2介质层去除速率的同时保持晶圆表面一致性,研究了SiO2/CeO2混合磨料的协同作用以及对SiO2介质层去除速率及一致性的影响。结果显示,相比于单一磨料,采用混合磨料能够兼顾介质去除速率和一致性。采用质量分数10%SiO2(粒径为80 nm)与质量分数0.7%CeO2磨料混合抛光后,对介质层的去除速率达到347 nm/min,片内非均匀性(WIWNU)为9.38%。通过场发射扫描电子显微镜(FESEM)观察颗粒状态发现,晶圆表面吸附大量的SiO2颗粒会阻碍CeO2磨料与晶圆表面接触,从而降低对晶圆中心的去除速率,使化学作用更均匀。通过将小粒径SiO2磨料(40 nm)与CeO2磨料混合,使介质层去除速率进一步提升至374 nm/min, WIWNU降低到8.83%,用原子力显微镜(AFM)表征抛光后晶圆... 相似文献
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热退火技术是集成电路制造过程中用来改善材料性能的重要手段。系统分析了两种不同的退火条件(氨气氛围和氧气氛围)对TiN/HfO2/SiO2/Si结构中电荷分布的影响,给出了不同退火条件下SiO2/Si和HfO2/SiO2界面的界面电荷密度、HfO2的体电荷密度以及HfO2/SiO2界面的界面偶极子的数值。研究结果表明,在氨气和氧气氛围中退火会使HfO2/SiO2界面的界面电荷密度减小、界面偶极子增加,而SiO2/Si界面的界面电荷密度几乎不受退火影响。最后研究了不同退火氛围对电容平带电压的影响,发现两种不同的退火条件都会导致TiN/HfO2/SiO2/Si电容结构平带电压的正向漂移,基于退火对其电荷分布的影响研究,此正向漂移主要来源于退火导致的HfO2/SiO2界面的界面偶极子的增加。 相似文献
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研究了在1-on-1方式下激光预处理对HfO2光学薄膜微观形貌、微观结构等性能的影响。实验采用薄 膜阈值能量的10%、50%%对HfO2薄膜进行激光预处理,利用原子力显微镜(AFM )分别对预处理后薄膜表面 10μm和3μm×3μm的区域进行测 试,与预处理前相比,预处理后的薄膜所含杂质减少,薄膜表面锥状结构变得平 滑;利用X射线衍射(XRD)和X射线光电子能谱(XPS)分别对预处理后薄膜的晶态结 构和化学键以及价态进 行测试,与预处理前相比,预处理后薄膜的晶态结构、化学键及价态均没有发生变化;利用 XPS对预处理后薄膜所含 的成分进行测试,与预处理前相比,预处理后薄膜中所含的Hf单质减少,HfO2增多。实验 结果表明,激光预处理具有抛光和氧化膜层的作用。 相似文献
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UV-assisted annealing processes for thin oxide films is an alternative to conventional thermal annealing and has shown many advantages such as low annealing temperature, reducing annealing time and easy to control. We report in this work the deposition of ultra-thin HfO2 films on silicon substrate by two CVD techniques, namely thermal CVD and photo-induced CVD using 222 nm excimer lamps at 400 °C. As-deposited films of around 10 nm in thickness with refractive indices from 1.72 to 1.80 were grown. The deposition rate measured by ellipsometry was found to be about 2 nm/min by UV-CVD, while the deposition rate by thermal CVD is 20% less than that by UV-CVD. XRD showed that the as-deposited HfO2 films were amorphous. This work focuses on the effect of post deposition UV annealing in oxygen on the structural, optical and electrical properties of the HfO2 films at low temperature (400 °C). Investigation of the interfacial layer by FTIR revealed that thickness of the interfacial SiO2 layer slightly increases with the UV-annealing time and UV annealing can convert sub-oxides at the interface into stoichiometric SiO2, leading to improved interfacial qualities. The permittivity ranges in 8–16, are lower than theoretical values. However, the post deposition UV O2 annealing results in an improvement in effective breakdown field and calculated permittivity, and a reduction in leakage current density for the HfO2 films. 相似文献
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K. McKenna A. Shluger V. IglesiasM. Porti M. NafríaM. Lanza G. Bersuker 《Microelectronic Engineering》2011,88(7):1272-1275
In this work, we combine conductive atomic force microscopy (CAFM) and first principles calculations to investigate leakage current in thin polycrystalline HfO2 films. A clear correlation between the presence of grain boundaries and increased leakage current through the film is demonstrated. The effect is a result of a number of related factors, including local reduction in the oxide film thickness near grain boundaries, the intrinsic electronic properties of grain boundaries which enhance direct tunnelling relative to the bulk, and segregation of oxygen vacancy defects which increase trap assisted tunnelling currents. These results highlight the important role of grain boundaries in determining the electrical properties of polycrystalline HfO2 films with relevance to applications in advanced logic and memory devices. 相似文献
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The electrical characteristics of HfO2-Ta2O5 mixed stacks under constant current stress (CCS) at gate injection with 20 mA/cm2 and stressing times of 50 and 200 s have been investigated. A very weak effect of the stress on the global dielectric constant, on fast and slow states in the stack as well as on the dominant conduction mechanism is detected. The most sensitive parameter to the CCS is the leakage current. The stress-induced leakage current (SILC) is voltage and thickness dependent. The pre-existing traps govern the trapping kinetics and are a key parameter to evaluate the stress response. Two processes - positive charge build-up and new bulk traps generation - are suggested to be responsible for SILC: the domination of one of them depends on both the film thickness and the stressing time. The positive charge build-up is localized close to the gate electrode implying gate-induced defects could be precursors for it. It is established that unlike the case of single SiO2 layer, the bulk traps closer to the gate electrode control SILC in the mixed Ta2O5-HfO2-based capacitors. 相似文献
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The impact of various rapid thermal annealing used during the integration on the La2O3/HfO2 and HfO2/La2O3 stacks deposited by Atomic Layer deposition was analyzed. The consequences of lanthanum localization in such stacks on the evolution of the films during the rapid thermal annealing are investigated in term of morphology, crystalline structure, silicate formation and film homogeneity as a function of the depth. It appeared that the La2O3 location has an impact on the temperature of the quadratic phase formation which could be linked to the formation of SiOHfLa silicate and the resistance of the films to dissolution in HF 0.05 wt%. 相似文献
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Current leakage and breakdown of MIM capacitors using HfO2 and Al2O3–HfO2 stacked layers were studied. Conduction in devices based upon HfO2 layers thinner than 8 nm is probably dominated by tunnelling. Al2O3–HfO2 stacked layers provide a limited benefit only in term of breakdown field. Constant-voltage wear-out of samples using insulating layer thicker than 6 nm is dominated by a very fast increase of the leakage current. A two step mechanism involving the generation of a conduction path followed by a destructive thermal effect is proposed to explain breakdown mechanism. 相似文献
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J.M. Decams H. Guillon C. Jimnez M. Audier J.P. Snateur C. Dubourdieu O. Cadix B.J. OSullivan M. Modreanu P.K. Hurley S. Rusworth T.J. Leedham H. Davies Q. Fang I. Boyd 《Microelectronics Reliability》2005,45(5-6):929
HfO2 films were deposited at low temperature (400 °C) by UV assisted injection metal-organic chemical vapor deposition (UVI-MOCVD). A three-step process was used for this study, consisting of (A) Pre-deposition anneal for nitridation; (B) Deposition step; (C) Post-deposition annealing in oxygen. Special attention was paid to the effect of UV exposure during these steps. Films were characterized by physical, optical and electrical techniques. Thickness was determined by different methods (X-ray Reflectrometry (XRR), spectroscopic ellipsometry and transmission electron microscopy) and a good agreement was found for all samples. The HfO2 permittivity, equivalent oxide thickness (EOT), flat-band voltage (Vfb) and total charge (Qt) were extracted from the CV response at high frequency taking into account the HfO2 and SiO2 thicknesses obtained by XRR. The calculated permittivity values were in the range 7–13, i.e. lower than theoretical values for the monoclinic phase. Explanations are suggested in the context of the other characterizations. JEeff characteristics were constructed taking into account the EOT values (Eeff = V/EOT). Effective breakdown fields range between 8.7 and 16.9 MV/cm. No dependence of Eeff with UV exposure was found. 相似文献
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Hf-O-N and HfO2 thin films were evaluated as barrier layers for Hf-Ti-O metal oxide semiconductor capacitor structures. The films were processed by sequential pulsed laser deposition at 300 °C and ultra-violet ozone oxidation process at 500 °C. The as-deposited Hf-Ti-O films were polycrystalline in nature after oxidation at 500 °C and a fully crystallized (o)-HfTiO4 phase was formed upon high temperature annealing at 900 °C. The Hf-Ti-O films deposited on Hf-O-N barrier layer exhibited a higher dielectric constant than the films deposited on the HfO2 barrier layer. Leakage current densities lower than 5 × 10 A/cm2 were achieved with both barrier layers at a sub 20 Å equivalent oxide thickness. 相似文献
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Hag-Ju Cho Chang Seok Kang Onishi K. Gopalan S. Nieh R. Rino Choi Krishnan S. Lee J.C. 《Electron Device Letters, IEEE》2002,23(5):249-251
A novel technique to control the nitrogen profile in HfO2 gate dielectric was developed using a reactive sputtering method. The incorporation of nitrogen in the upper layer of HfO2 was achieved by sputter depositing a thin HfxNy layer on HfO2, followed by reoxidation. This technique resulted in an improved output characteristics compared to the control sample. Leakage current density was significantly reduced by two orders of magnitude. The thermal stability in terms of structural and electrical properties was also enhanced, indicating that the nitrogen-doped process is effective in preventing oxygen diffusion through HfO2. Boron penetration immunity was also improved by nitrogen-incorporation. It is concluded that the nitrogen-incorporation process is a promising technique to obtain high-k dielectric with thin equivalent oxide thickness and good interfacial quality 相似文献
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HfO2 dielectric films with a blocking layer (BL) of Al2O3 on Si0.8Ge0.2 were treated with rapid thermal annealing process. The effect of BL on thermal stability and electrical properties was reported. X-ray photoelectron spectroscopy suggested that BL could suppress the further growth of the interfacial layer composed of SiOx and GeOx, and lead to the decomposition of GeOx and the saturation of O vacancy in SiOx structure. High-resolution transmission electron microscopy indicated that BL would keep HfO2 amorphous after annealed treatment. Electrical measurements indicated that there was no stretch-out in capacitance-voltage curves, the accumulation region was flat, and leakage current was reduced for the sample with BL. 相似文献