标题: 三维积体电路之超薄缓冲层技术于铜/锡接合研究及开发
Development and Investigation of Ultra-Thin Buffer Layers Used in Cu/Sn Bonding for Advanced 3D Integration Applications
作者: 陈秀齐
陈冠能
Chen, Hsiu-Chi
Chen, Kuan-Neng
电子研究所
关键字: 三维积体电路;接合;超薄缓冲层;铜锡接合;3DIC;Bonding;Ultra-thin buffer layer;Cu/Sn bonding
公开日期: 2017
摘要: 铜/锡接合结构受限于金属间的快速相互扩散而无法降低焊锡用量。为了解决这个问题,本篇论文使用超薄缓冲层于铜锡次微米薄膜接合,以减缓共晶接合前的相互扩散现象。为了提高未来实际应用的多元性,不同材料(镍、钴、钛、钯)及不同厚度(10 奈米至100奈米)的超薄缓冲层会分别在这篇论文中被讨论。为了评估超薄缓冲层的缓冲能力,我们藉由欧杰电子能谱仪进行元素纵深分析观察铜锡相互扩散程度。研究结果成功开发出使用镍或钴为超薄缓冲层的晶圆级铜锡薄膜共晶接合。除了接合强度测试以外,本研究除了利用多种材料分析手法探讨其接合品质,并且经由电性特性及可靠度测试,发现此接合结构不只表现良好的晶圆级均匀性,并且对高热应力、高湿度具有良好的可靠度。除此之外,使用超薄缓冲层应用于非对称铜锡-铜接合的结构也被成功开发,并且展现较对称铜锡接合结构更好的可靠度特性。
  综合以上,超薄缓冲层的多元应用价值可望在未来被应用于先进三维积体整合。
In order to achieve submicron Cu/Sn bonding to keep up with the trend of transistors scaling, a particular ultra-thin buffering layer (UBL) is inserted between Cu and Sn to delay the interdiffusion before eutectic bonding. Various different materials and thickness ranging from 10 nm to 100 nm of UBL are thoroughly studied in this research. To increase the flexibility of this Cu/Sn bonding scheme for advanced 3D integration application, some CMOS compatible materials including Co, Pd and Ti are also discussed. Successful wafer-level Cu/Sn bonding with Ni UBL and Co UBL are demonstrated. Several kinds of material analysis are conducted to evaluate the bonding results while the buffering ability of the different materials are evaluated by Auger depth profile analysis. In addition to symmetric Cu/Sn bonding with UBL, asymmetric Cu/Sn-Cu bonding with Ni UBL, which is found with better reliability, is also demonstrated.
With electrical performance examination and reliability tests (TCT and HAST), Cu/Sn bonded structures with UBL show not only an excellent uniformity on wafer-level but also good reliability. Above all, the application of UBL used in soldering technology gives a promising and flexible platform for future 3D integration applications.
URI: http://etd.lib.nctu.edu.tw/cdrfb3/record/nctu/#GT070450111
http://hdl.handle.net/11536/141081
显示于类别:Thesis