【作者】 俞笑竹；

【导师】 宁兆元； 叶超；

【作者基本信息】 苏州大学 ， 凝聚态物理， 2006， 硕士

【摘要】 通过在前驱气体D5源中添加甲烷，由ECRCVD沉积技术制备出了低介电常数的SiCOH薄膜，在甲烷流量为2sccm的条件下，获得了k值为2.45的薄膜样品。由FTIR和OES分析结果，我们推测：富碳氢的等离子体环境可能有利于D5骨架的保留。薄膜结构中大量碳氢大分子基团的引入，通过Si-C，C-C键连接相邻的单环，提高了薄膜的交连程度，使得膜的密度降低，介电常数持续减小。 将制备出的薄膜分别在大气和氮气气氛下退火处理，研究了退火气氛对薄膜结构和性能的影响。在退火处理过程中，薄膜一方面与退火气氛中的活性物质发生反应，另一方面在高温作用下发生结构重组。大气条件下退火的薄膜样品以类SiO₂结构为主，强极性Si-OH键的生成和薄膜的剧烈收缩导致介电常数的上升。氮气条件下退火后的薄膜中形成了较多的链式结构，交联程度降低是引起介电常数增大的主要原因。更多还原

【Abstract】 Low-k SiCOH films are prepared by electron cyclotron resonance chemical vapor deposition (ECR-CVD) by adding methane in decamethylcyclopentasioxane (D5) as source gas, and the lowest dielectric constant 2.45 is obtained when flow rate of methane is 2sccm. According to the analysis of FTIR and OES results, we speculate that the plasma environment rich in carbon and hydrogen is beneficial to the conservation of annular framework of D5. Large quantities of carbon and hydrogen element form Si-C and C-C bonds in the films connecting adjacent annular framework, which would decrease film density and cause continually decrease in dielectric constant.The influence of anneal atmosphere on structure and properties of films is investigated by annealing films respectively in air and nitrogen. In this process, films react with the active element in anneal atmosphere and recombine structure because of the high temperature. The film annealed in air is similar to silicon dioxide in structure. The appearance of polar bond Si-OH and the shrinkage of film cause the increase of dielectric constant. Many chain link structures form in the film annealed in nitrogen. Decrease of connecting networks is the main reason for the increase of dielectric constant.更多还原