Laboratoire de Physique de l'Etat Condensé, UMR 6087 CNRS-Université du Maine, Le Mans, France.
ACS Nano. 2012 Feb 28;6(2):1410-5. doi: 10.1021/nn204210u. Epub 2012 Jan 17.
Revealing defects and inhomogeneities of physical and chemical properties beneath a surface or an interface with in-depth nanometric resolution plays a pivotal role for a high degree of reliability in nanomanufacturing processes and in materials science more generally. (1, 2) Nanoscale noncontact depth profiling of mechanical and optical properties of transparent sub-micrometric low-k material film exhibiting inhomogeneities is here achieved by picosecond acoustics interferometry. On the basis of the optical detection through the time-resolved Brillouin scattering of the propagation of a picosecond acoustic pulse, depth profiles of acoustical velocity and optical refractive index are measured simultaneously with spatial resolution of tens of nanometers. Furthermore, measuring the magnitude of this Brillouin signal provides an original method for depth profiling of photoelastic moduli. This development of a new opto-acoustical nanometrology paves the way for in-depth inspection and for subsurface nanoscale imaging of inorganic- and organic-based materials.
揭示表面或界面下物理和化学性质的缺陷和不均匀性对于纳米制造过程和更广泛的材料科学的高度可靠性起着关键作用。(1, 2) 本文采用皮秒声学干涉法实现了对具有不均匀性的亚微米低 k 材料薄膜的机械和光学性能的纳米级非接触深度剖面分析。基于通过皮秒声脉冲传播的时间分辨布里渊散射进行光学检测，同时测量了声学速度和光学折射率的深度分布，空间分辨率为几十纳米。此外，测量该布里渊信号的幅度提供了一种用于光学弹性模量深度剖面分析的原始方法。这种新型光声纳米计量学的发展为无机和有机基材料的深入检查和亚表面纳米成像铺平了道路。
