【作者】 叶超；

【导师】 宁兆元；

【作者基本信息】 苏州大学 ， 凝聚态物理， 2006， 博士

【摘要】 微电子器件在快速发展，器件的性能不断完善，集成度不断提高，预计到2010年后进入45nm以下线宽的纳电子器件时代。由于高性能芯片上器件密度和连线密度的增加，器件尺寸和线宽将减小，导致互连线的阻容（RC）增大、信号传送延时、噪声干扰增强和功率耗散增大，器件工作频率受到限制。为了解决这些问题，人们正在发展新的互连材料、新的互连结构以及新的互连方式。采用新的互连材料来取代目前的Al／SiO₂已成为解决纳电子器件互连问题的主要选择。作为互连介质的低k材料和超低k材料，是近年来全球微电子材料与器件领域关注的焦点之一。 我们研究小组从2003年起在国际上率先将环结构的十甲基环五硅氧烷（DMCPS）反应源与微波电子回旋共振（ECR）等离子体技术相结合，开展了基于孔隙的低介电常数SiCOH薄膜的研究。另一方面，在保持适度孔隙率的前提下，通过CHF₃、CH₄的掺杂，进一步开展了弱极化键与孔隙相结合的低介电常数SiCOH薄膜的研究。本论文对SiCOH薄膜的结构特征作了分析，建立了薄膜介电性能的结构关联，探索了薄膜结构与放电等离子体之间的关联，获得了重要的研究结果： 1、采用电子回旋共振等离子体技术、以DMCPS液体源为前驱物和适当的掺杂工艺制备了k=2.45、膜厚收缩率小于3％的性能优良的低介电常数SiCOH薄膜。总结了磁场形态、源气体流量比对薄膜性能的影响，提出获得低介电常数SiCOH薄膜的技术途径。 2、研究了基于孔隙的SiCOH薄膜的结构与形成条件。通过选择适当的放电条件，将DMCPS源中固有的环结构在薄膜中保存，并相互交联形成由硅氧键构成的立体笼子结构，从而在薄膜中形成孔隙，成为降低SiCOH薄膜介电常数的主要途径。研究发现，采用DMCPS源、利用ECR等离子体沉积的SiCOH薄膜分为含有Si-OH结构、无Si-OH结构的两类典型。由于Si-OH结构的存在不利于薄膜介电常数的降低，控制和降低薄膜中Si-OH基团含量成为获得低介电常数薄膜的重要前提。实验中通过提高微波能量耦合效率，来提高电子能量，使更多的Si-OH键断裂而相互交联形成Si-O-Si网络，是降低薄膜中Si-OH基团含量的可行途径。为了提高硅氧立体笼子结更多还原

【Abstract】 The rapid development of microelectronic devices will lead to the continuous improvement of device performance and the increase of device integrated on a chip. The line size below 45 nm will be achieved and the nano-electronic device will occur by 2010. In order to reduce the RC sign delay, dissipation and cross-link between metal interconnects caused by size shrinking continuously, the porous low dielectric constant （low-k） and ultra-low dielectric constant （uItralow-k, k < 2） material recently received more close attention.From 2003, we use decamethylcyclopentasiloxane （DMCPS） electron cyclotron resonance （ECR） plasma to prepare pore-based SiCOH low-k films. Then we develop a new method combined weak polarization bonds with pores to prepare SiCOH low-k films by incorporating CHF₃ or CH₄ in porous SiCOH films. In the thesis, the films bonding configurations, the effect of structures on dielectric property, and the relationship between films structure and discharge plasma behavior are analyzed. The details are as follows.1. The SiCOH low-k films with k = 2.45 and good thermal stability have been prepared by DMCPS ECR plasma and CHF, or CH, doped. By analyzing the effect of field distribution and source gases flow on films structures and dielectric property, the method to reduce dielectric constant is presented.2. For the pore-based SiCOH films, the porosity can be increased by optimizing discharge condition to preserve the ring structure in the films and further form the cage in the films by linking rings each other. This becomes an available method to reduce dielectric constant. We found that the SiCOH films prepared only by DMCPS show two types of typical bonding configurations, including with and free of Si-0 groups in the films. Due to the strong polarization of Si-OH group, it leads to the increase of k value of the SiCOH films. At the case of high ionization degree of precursor, more Si-OH更多还原