空气隙Cu互连结构热应力史研究

将空气引入Cu导线间形成空气隙,可有效降低等效介电常数K_(eff),但同时也使互连结构的机械稳定性面临着挑战。利用ANSYS进行了有限元热分析,研究了制备空气隙Cu互连结构的两种主流工艺过程,即CVD沉积法和热分解牺牲层法,模拟了Cu导线上的热应力变化趋势,并比较了两者的优劣,最终发现互连结构经过一系列热应力的循环作用后,各种材料在不同程度上都有较大的形变,这将影响结构的机械稳定性,甚至引起破坏。所以,需要进一步改善结构设计和使用理想电介质。

Study on Thermal Stress History in Air-Gap/Cu Interconnect

The introduction of air-gaps between copper wires can effectively reduce the equivalent dielectric constant K_(eff),but the mechanical stability of interconnect structure is also facing challenges. ANSYS finite element thermal analysis is used,through studying two kinds of mainstream processes for manufacturing the air-gap/Cu interconnect structure,CVD deposition method and thermal decomposition of the sacrificial layer method,to simulate the thermal stress history on the copper wire,and the pros and cons a...