• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Comparison of high power impulse magnetron sputtering and modulated pulsed power sputtering for interconnect metallization.
【24h】

Comparison of high power impulse magnetron sputtering and modulated pulsed power sputtering for interconnect metallization.

机译：用于互连金属化的高功率脉冲磁控溅射和调制脉冲功率溅射的比较。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Ionized physical vapor deposition is used to deposit the barrier and seed layers in the state of the art interlevel metallization process. An enhanced metal ionization is believed to be critical. Ions in the deposition flux can increase the nucleation density and adhesion of Cu to Ta due to their surface penetration, and create less overhang due to the high directionality of ion flux. In this work, high power impulse magnetron sputtering (HiPIMS) and its derivative, modulated pulsed power (MPP) magnetron sputtering, with their claimed high ionization capability, are proposed for the application of barrier/seed layer deposition. Their plasma properties and metal ionization fractions are characterized using various pulsing and discharge parameters. Depositions on patterned wafers are performed to evaluate their potential for interconnect metallization application. Time- and spatially-resolved plasma diagnostics are further performed to investigate the physical mechanisms involved in the pulsed plasma generation, evolution, and plasma transport. Specially designed experiments and plasma modeling are used to further understand some key features during HiPIMS, such as the self-sputtering process. Fundamental studies of HiPIMS discharge are conducted in a planar magnetron. Very high peak current up to 750 A can be achieved. Triple Langmuir probe (TLP) is adopted to measure the electron density ne and electron temperature Te. High electron densities (ne) during the pulse to about 5x1017 m-3 are measured on the substrate and reach 3x1018 m-3 later after the pulse ends. Cu ionization fractions (IF) are measured on the substrate level using a gridded energy analyzer (GEA) combined with a quartz crystal microbalance (QCM). Up to 60% has been achieved using a 200 Gauss magnetic field configuration, much higher than the DC magnetron sputtering. It basically increases with higher charging voltage and longer pulse length due to higher plasma densities. However, lower ion extraction efficiency at stronger B field, however, leads to lower Cu ionization in spite of a higher plasma density. HiPIMS has been shown to have some complicated and distinctive features. Different parameters such as the charging voltage, pulse duration, and magnetic field strength are found to affect the plasma transport. A large plasma potential drop is observed in the presheath and extends into the bulk plasma region during HiPIMS discharge. It not only affects the plasma expansion but also determines the ion extraction efficiency, which is critical for the interconnect metallization application. A direct evidence of the self-sputtering effect is provided by measuring the incident fluxes to the cathode through a hole in the target. Plasma is initially ignited only in a long strip in the race track where the B field is strong and drifts toward the weak-B region. High fraction of Cu+ flux is determined. To provide more insights into the development of Cu ion and Ar ion species, a time-dependent model is built to describe the ionization region where plasma is confined by magnetic field. The important processes such as plasma-target interactions, electron collision ionizations, and gas rarefaction are incorporated in the model. The test results of the model show the capability to predict the temporal development of the electron density, the degrees of ionization for Cu and Ar, and the ratio of Cu+ ions to Ar+ ions. Magnetic field configurations are modified specifically for the HIPIMS. The race track pattern is varied to optimize the target utilization and the downstream plasma uniformity. A closed path for electrons to drift along is found essential in the design. The configuration of wider race track generates a higher pulse current, and extends the intense plasma coverage on the substrate. In this study, a thorough characterization of the MPP discharge using two different models (Solo and Cyprium) is performed in the Galaxy planar magnetron to better understand this pulsing technique. For the test of deposition on patterned wafers, a hollow cathode magnetron is chosen. All three types of power supplies, DC, MPP and HiPIMS are first subject to the plasma characterization, both to study the discharge mechanisms on HCM and to develop potentially good recipes with high Cu ionization fractions. Both MPP and HiPIMS increase the Cu ionization fraction in the deposition flux (up to 25% and up to 30% respectively) as compared with the normal DC magnetron sputtering (as below 20%). Ultimately, Cu is deposited on patterned wafers with trenches of different widths as narrow as 70 nm. The conformality of the Cu film on the trench will be compared using cross-section scanning electron microscopy (SEM). Reduced overhang is achieved using MPP Solo as compared with DC sputtering. The potential of applying HiPIMS and MPP for barrier/seed layer deposition will be further discussed.
机译：在现有的层间金属化工艺中，电离物理气相沉积用于沉积势垒层和晶种层。增强的金属电离被认为是至关重要的。沉积通量中的离子由于其表面渗透性，可以增加成核密度和Cu对Ta的附着力，并且由于离子通量的高方向性而产生的悬垂较少。在这项工作中，提出了具有声称的高电离能力的高功率脉冲磁控溅射（HiPIMS）及其派生的调制脉冲功率（MPP）磁控溅射，以用于势垒/种子层沉积。使用各种脉冲和放电参数来表征它们的等离子体特性和金属电离分数。执行在图案化晶片上的沉积以评估其在互连金属化应用中的潜力。进一步进行时间和空间分辨的等离子体诊断，以研究涉及脉冲等离子体生成，演化和等离子体传输的物理机制。经过特殊设计的实验和等离子体建模可进一步了解HiPIMS的一些关键功能，例如自溅射工艺。 HiPIMS放电的基础研究是在平面磁控管中进行的。可以实现高达750 A的非常高的峰值电流。采用三重朗缪尔探针（TLP）测量电子密度ne和电子温度Te。在基板上测量到大约5x1017 m-3的脉冲期间的高电子密度（ne），并在脉冲结束后达到3x1018 m-3。铜离子化分数（IF）使用结合了石英晶体微量天平（QCM）的网格化能量分析仪（GEA）在基板水平上进行测量。使用200高斯磁场配置可达到60％，远高于直流磁控溅射。由于较高的等离子体密度，它基本上随较高的充电电压和较长的脉冲长度而增加。然而，尽管等离子体密度较高，但在较强的B场处较低的离子提取效率会导致较低的Cu电离。已证明HiPIMS具有一些复杂而独特的功能。发现诸如充电电压，脉冲持续时间和磁场强度之类的不同参数会影响等离子体的传输。在HiPIMS放电期间，在前皮中观察到较大的等离子体电势下降，并延伸到整个等离子体区域。它不仅影响等离子体膨胀，而且还决定了离子提取效率，这对于互连金属化应用至关重要。通过测量通过靶中孔向阴极的入射通量，可以提供自溅射效应的直接证据。最初，仅在B场强且向弱B区域漂移的赛道中的长条中点燃等离子体。确定了高比例的Cu +助焊剂。为了提供有关Cu离子和Ar离子种类发展的更多见解，建立了一个时变模型来描述电离区域，在该区域中等离子体受磁场限制。模型中包含了重要的过程，例如等离子体与目标的相互作用，电子碰撞电离和气体稀化。该模型的测试结果显示了预测电子密度，Cu和Ar的电离度以及Cu +离子与Ar +离子之比的时间发展能力。磁场配置专门针对HIPIMS进行了修改。改变跑道图案以优化目标利用率和下游等离子体均匀性。在设计中必须找到一条封闭的电子漂移路径。较宽的跑道的配置产生较高的脉冲电流，并扩展了基板上的强烈等离子体覆盖范围。在这项研究中，在银河平面磁控管中使用两种不同的模型（Solo和Cyprium）对MPP放电进行了全面的表征，以更好地了解这种脉冲技术。为了测试在图案化晶片上的沉积，选择了空心阴极磁控管。首先要对所有三种类型的电源DC，MPP和HiPIMS进行等离子体表征，以研究HCM的放电机理并开发具有高Cu电离分数的潜在好的配方。与普通的直流磁控溅射（低于20％）相比，MPP和HiPIMS都增加了沉积通量中的铜离子化分数（分别高达25％和高达30％）。最终，将铜沉积在具有宽至70 nm的不同宽度沟槽的图案化晶圆上。将使用截面扫描电子显微镜（SEM）比较沟槽上的Cu膜的保形性。与直流溅射相比，使用MPP Solo可以减少悬伸。将进一步讨论将HiPIMS和MPP用于阻挡层/种子层沉积的潜力。

著录项

  • 作者

    Meng, Liang.;

  • 作者单位

    University of Illinois at Urbana-Champaign.;

  • 授予单位 University of Illinois at Urbana-Champaign.;
  • 学科 Engineering Nuclear.;Engineering Materials Science.;Engineering Electronics and Electrical.
  • 学位 Ph.D.
  • 年度 2013
  • 页码 172 p.
  • 总页数 172
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号