铜互连多层膜系中自对准CuSiN层的微结构及其热稳定性

MICROSTRUCTURE AND THERMAL STABILITY OF CuSiN SELF-ALIGNED LAYER IN ADVANCED COPPER INTERCONNECT MULTILAYER FILMS

通过等离子体与Cu膜表面的分步反应合成了厚约4nm的CuSiN自对准层.采用高分辨透射电子显微术(HRTEM)、纳米电子束探针能谱(EDS)和X射线衍射(XRD)表征CuSiN和Si/SiO_2/TaN/Ta/Cu(CuSiN)/SiC:H/SiOC:H多层膜基体系的微结构和热稳定性.表明CuSiN层两侧分别出现SiN和Cu(Si)层,显著提高Cu/SiC:H/SiOC:H结构的热稳定性,其机制是在500℃退火温度条件下CuSiN层仍能够稳定存在,从而阻碍了Cu原于向SiC:H/SiOC:H介质薄膜体内的扩散.

A CuSiN self-aligned layer with 4 nm in thickness was synthesized by a step-reaction between plasma and Cu film surface in RF-plasma-enhanced chemical vapor deposition system. The microstructure of Si/SiO2/TaN/Ta/Cu（CuSiN）/SiC ： H/SiOC ： H multi-layer stacks was investi- gated by using HRTEM, EDS and XRD. The results indicate that SiN and Cu（Si） layers appeared in bothsides of CuSiN layer, and the thermal stability of the interface of Cu/SiC ： H dielectric barriers can be improved by introducing CuSiN self-aligned layer which suppressed copper atom or vacancy diffusion into SiC ： H/SiOC ： H dielectric film along the interface.