在双镶嵌铜互联中0.13微米器件生成用的基于PVD和ALD阻挡层的先进技术(英文)

1. IntroductionThe requirement of minimal bottom coverageand thick sidewall coverage for PVD-based films forlow via resistance and improved stress migration isnot easy to achieve with traditional depositionmethods. Modern I-PVD techniques give high bot-tom coverage, due to the ionized component of thedeposition flux. Sidewall coverage tends to be low,which is mainly due to off-normal deposition fluxand a less than unity sticking coefficient.Early research into ionized PVD depositionshowed…     

铜互连布线及其镶嵌技术在深亚微米IC工艺中的应用

近几年来 ,随着 VLSI器件密度的增加和特征尺寸的减小 ,铜互连布线技术作为减小互连延迟的有效技术 ,受到人们的广泛关注。文中介绍了基本的铜互连布线技术 ,包括单、双镶嵌工艺 ,CMP工艺 ,低介电常数材料和阻挡层材料 ,及铜互连布线的可靠性问题     

Failure mechanisms of PVD Ta and ALD TaN barrier layers for Cu contact applications

PVD Ta-based and ALD TaN layers were studied as Cu diffusion barriers on poly-silicon, NiSi and CoSi₂ for Cu contact applications. The effectiveness of nanometer-thick layers, deposited in manufacturing compatible chambers on 200 and 300 mm wafers, is evaluated by detection of Cu-silicidation temperature using high temperature in situ XRD. It is found that Si diffuses into the α-Ta lattice for PVD barriers between 300 and 500 °C, and induces Ta silicidation at 600 °C. The agglomeration of TaSi₂ seems to be responsible for the damage of barrier continuity and cause subsequent Cu-silicidation. The growth of ALD TaN on different surfaces of NiSi was studied by XRF, RBS and XRR. The growth curves show excellent linearity as a function of thickness. TOF-SIMS shows closed layers after 60 ALD cycles. In situ XRD reveals that the failure temperature of 4 nm thick ALD layers is higher than 500 °C. It is found that the failure of 3 and 4 nm ALD TaN layers in Cu/barrier/NiSi stacks is a diffusion controlled process, with an activation energy Q of ∼2.2 eV and a pre-exponential factor D₀ of ∼3.8 × 10⁻³ cm²/s.     

SiGeHBT的二维数值模拟分析设计

采用适合于亚微米器件模拟的流体动力学模型 (HDM) ,对 Si Ge HBT的亚微米器件模拟软件进行了设计。在 SMDS1.0模拟软件 [1]的基础之上 ,软件的设计仍采用面向对象技术 ,因而该软件仍将保持良好的可扩展性等特点 ,并可简单扩展应用于其他亚微米器件的模拟     

使用氩离子击穿PVD阻挡层工艺提高90nm双大马真士革互联的参变量和可靠性

随着金属导线线宽的不断缩小,在90nm 技术以下,刻蚀残留物的存在会在应力迁移测试中形成高通孔电阻和空洞成核现象。物理氩离子预清洗是一种去除残留物的有效方法。但在应力迁移测试中发现,底部沟槽铜的二次溅射会导致器件的早期失效。反应性预清洗方法由于含有H +、H 类粒子而在减少C uO x 和清洗Si,N ,F,C ,O ,等蚀刻残留物时表现出其优越性。提出了针对传统PV D 工艺的反应性预清洗及PV D 击穿(沉积,刻蚀,沉积)工艺的解决方案。阻挡层击穿工艺减少了通孔电阻,提高了应力迁移性能,并通过薄钽沉积工序防止了铜的扩散从而保护了双嵌入斜面和错位通孔。此外,使电子阻塞和局部加热效应最小化的U 型界面,提高了电子迁移失效的平均时间,一致的、可重复的覆盖膜特性和良好的电参量测试结果已经证实了这种工艺的生产价值。     

柠檬酸在钴基铜互连CMP及后清洗的研究进展

钴(Co)具有较低的电阻率、良好的热稳定性、与铜(Cu)粘附性好等优点,可以替代钽(Ta)成为14 nm以下技术节点集成电路(IC) Cu互连结构的新型阻挡层材料。化学机械抛光(CMP)是唯一可以实现Cu互连局部和全局平坦化的方法,也是决定Co基Cu互连IC可靠性的关键技术。柠檬酸含有羟基,在电离后对金属离子有较强的络合作用,成为Co基Cu互连CMP及后清洗中的主要络合剂。文章评述了柠檬酸在Cu互连CMP及后清洗中的应用和研究进展,包括柠檬酸对Cu/Co去除速率选择比、Co的表面形貌以及Co CMP后清洗中Co表面残留去除等方面的影响,并展望了络合剂及Cu互连阻挡层CMP的发展趋势。     

Synthesis and Characterization of SiCOF/a-C∶F Double-Layer Films with Low Dielectric Constant for Copper Interconnects

用等离子体化学气相淀积系统制备了一种新颖的SiCOF/a-C:F双层低介电常数介质薄膜,并用红外光谱表征了该薄膜的化学结构.通过测量介质的折射率发现该薄膜长时间暴露在空气中,其光频介电常数几乎不变.然而,随退火温度的增加,其光频介电常数则会减小.基于实验结果讨论了几种可能的机理.二次离子质谱分析表明在Al/a-C:F/Si结构中F和C很容易扩散到Al中,但在Al/SiCOF/a-C:F/Si结构中,则没有发现C的扩散,说明SiCOF充当了C扩散的阻挡层.分析还发现在SiCOF和a-C:F之间没有明显的界面层.     

The Application of Barrierless Metallization in Making Copper Alloy,Cu(RuHfN), Films for Fine Interconnects

In this study, films of a copper (Cu) alloy, Cu(RuHfN _x ), were deposited on silicon (Si) substrates with high thermal stability by co-sputtering copper and minute amounts of Hf or Hf/Ru in an Ar/N₂ gas mixture. The Cu(RuHfN _x ) films were thermally stable up to 720°C; after annealing at 720°C for 1 h, the thermal stability was great enough to avoid undesired reaction between the copper and the silicon. No copper silicide was formed at the Cu–Si interface for the films after annealing at 720°C for 1 h. The Cu(RuHfN _x ) films appear to be good candidate interconnect materials.     

铜互连中SiCOF/a-C:F双层低介电常数薄膜的制备和表征

用等离子体化学气相淀积系统制备了一种新颖的SiCOF/a-C:F双层低介电常数介质薄膜,并用红外光谱表征了该薄膜的化学结构.通过测量介质的折射率发现该薄膜长时间暴露在空气中,其光频介电常数几乎不变.然而,随退火温度的增加,其光频介电常数则会减小.基于实验结果讨论了几种可能的机理.二次离子质谱分析表明在Al/a-C:F/Si结构中F和C很容易扩散到Al中,但在Al/SiCOF/a-C:F/Si结构中,则没有发现C的扩散,说明SiCOF充当了C扩散的阻挡层.分析还发现在SiCOF和a-C:F之间没有明显的界面层.     

Comprehensive Chemistry Designs in Porous SiOCH Film Stacks and Plasma Etching Gases for Damageless Cu Interconnects in Advanced ULSI Devices

High performance Cu dual-damascene (DD) interconnects without process-induced damages are developed in porous SiOCH stacks with the effective dielectric constant $(k _{rm eff})$ of 2.95, in which a carbon (C)-rich molecular-pore-stacking (MPS) SiOCH film $(k=2.5)$ is stacked directly on an oxygen (O)-rich porous SiOCH $(k=2.7)$ film. The novel etch-stopperless structure is obtained by comprehensive chemistry design of C/O ratios in the SiOCH stack and the etching plasma of an ${hbox{Ar}}/ {hbox{N}} _{2} / {hbox{CF}} _{4} / {hbox{O}} _{2}$ gas mixture technique. Large hydrocarbons attached to hexagonal silica backbones in the MPS–SiOCH prevent the Si–CHx bonds from oxidation during ${hbox{O}} _{2}$-plasma ashing, suppressing the C-depleted damage area at the DD sidewall. Combining multiresist mask process with immersion ArF photolithography, strictly controlled Cu DD interconnects with 180-nm pitched lines and 65-nm-diameter vias are obtained successfully, ready for the 300-mm fabrication.      

Advanced Functional Biomaterials for Stem Cell Delivery in Regenerative Engineering and Medicine

Stem cell–based therapies can potentially regenerate many types of tissues and organs, thereby providing solutions to a variety of diseases and injuries. However, acute cell death, uncontrolled differentiation, and low functional engraftment yields remain critical obstacles for clinical translation. Advanced functional biomaterial scaffolds that can deliver stem cells to the targeted tissues/organs and promote stem cell survival, differentiation, and integration to host tissues may potentially transform the clinical outcome of stem cell–based regenerative therapies. In this review, the authors briefly summarize sources of stem cells for transplantation, present the current state of the art in biomaterial design for stem cell delivery, and provide critical analysis for existing materials. Applications to the cardiovascular, neural, and musculoskeletal systems are highlighted with recent nonclinical studies and clinical trials. The authors also discuss how advances in biomaterials research can contribute to regenerative medicine research and stem cell therapies.