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

铜互连中SiCOF/a-C∶F双层低介电常数薄膜的制备和表征(英文)

作　　者：张卫[1] 朱莲[1] 孙清清[1] 卢红亮[1] 丁士进[1] 

机构地区：[1]复旦大学微电子学系,上海200433

出　　处：《Journal of Semiconductors》2006年第3期429-433,共5页半导体学报（英文版）

基　　金：国家自然科学基金(批准号:60176013);上海先进材料研究发展基金(批准号:0304)资助项目~~

摘　　要：A novel double-layer film of SiCOF/a-C ： F with a low dielectric constant is deposited using a PECVD system. The chemical structure of the film is characterized with Fourier transform infrared spectroscopy （FTIR）. The measurements of the film refractive index reveal that the optical frequency dielectric constant （n^2） of the film is almost constant as a function of air exposure time, however, with increasing annealing temperature, the value of n^2 for the film decreases. Possible mechanisms are discussed in detail. The analysis of SIMS profiles for the metal-insulator-silicon structures reveal that in the Al/a-C ： F/Si structure,the annealing causes a more rapid diffusion of F in AI in comparison with C, but there is no obvious difference in Si. In addition, no recognizable verge exists between SiCOF and a-C ： F films,and the SiCOF film acts as a barrier against the diffusion of carbon into the aluminum layer.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.

关 键 词：low dielectric constant material FTIR SIMS 

分 类 号：TN304[电子电信—物理电子学]