Yang, Zehua; Zhu, Jingtao; Zhu, Yunping; Luo, Hongxin; Li, Zhongliang; Jiang, Hui; Zhao, Li

APPLIED SURFACE SCIENCE

2022, 604, 0169-4332

Yang, Zehua; Zhu, Jingtao; Zhu, Yunping; Luo, Hongxin; Li, Zhongliang; Jiang, Hui; Zhao, Li

This paper presents a comparative study on W/Si and WSi2/Si multilayers for analyzing the asymmetric inter-facial effect in Si-based multilayers. The interfacial characteristic, crystallization and growth mechanism of W/Si and WSi2/Si multilayers were investigated using grazing incidence X-ray reflectivity, X-ray diffraction, X-ray diffuse scattering, total external reflection X-ray diffuse scattering and Transmission Electron Microscopy. Roughness characteristics including frequency response, conformity and replication were quantitatively deter-mined from the simulation of diffuse scattering profiles and the calculation of resonant diffuse scattering sheets. The intrinsic power spectral density of W/Si and WSi2/Si multilayers was fitted to demonstrate the related growth mechanism of the interfacial roughness. The experimental results exhibit the diffusion-dominant interfaces of the W/Si multilayer are obvious asymmetric for the wider interfacial region of 0.37 nm in the W-on-Si interface than that of 0.28 nm in the Si-on-W interface. Interfaces of the WSi2/Si multilayer without the distinguishable interdiffusion present the roughness-dominant property with the asymmetric transverse relaxation. The asymmetric interfaces of W/Si and WSi2/Si multilayers were further interpreted by a modified ballistic argument with the interfacial relaxation and reaction analysis.