Response of thin films and substrate to micro scale laser shock peening

Abstract

Micro scale laser shock peening (µLSP) can potentially be applied to metallic structures in micro devices to improve fatigue and reliability performance. Copper thin films on single-crystal silicon substrate are treated by using µLSP and characterized using techniques of X-ray micro-diffraction and electron backscatter diffraction (EBSD). Strain field, dislocation density and microstructure changes including crystallographic texture, grain size and subgrain structure are determined and analyzed. Further, shock peened single crystal silicon was experimentally characterized to better understand its effects on thin films response to µLSP. The experimental result is favorably compared with FEM simulation based on single crystal plasticity.Micro scale laser shock peening (µLSP) can potentially be applied to metallic structures in micro devices to improve fatigue and reliability performance. Copper thin films on single-crystal silicon substrate are treated by using µLSP and characterized using techniques of X-ray micro-diffraction and electron backscatter diffraction (EBSD). Strain field, dislocation density and microstructure changes including crystallographic texture, grain size and subgrain structure are determined and analyzed. Further, shock peened single crystal silicon was experimentally characterized to better understand its effects on thin films response to µLSP. The experimental result is favorably compared with FEM simulation based on single crystal plasticity.