The surface crack of single-crystal silicon induced by a millisecond laser
When the silicon material is irradiated by laser,it absorbs the laser energy leading to the temperature rise and the thermal stress.The damage effect includes melting,vaporation and thermal stress damage.Once the thermal stress exceeds the stress strength the crack will initiate.The silicon surface cracks induced by a millisecond laser are investigated.The experimental results show that three types of cracks are generated including cleavage crack,radial crack and circumferential crack.The cleavage crack is located within the laser spot.The radial crack and circumferential crack are located outside the laser spot.A two-dimensional spatial axisymmetric model of silicon irradiated by a 1064nm millisecond laser is established.To assess what stresses generate and explain the generation mechanism of the different cracks,the thermal stress fields during laser irradiation and the cooling process are obtained using finite element method.The radial stress and hoop stress within the laser spot are tensile stress after the laser irradiation.The temperature in the center is the highest but the thermal stress in the center is not always highest during the laser irradiation.The cleavage cracks are induced by the tensile stress after the laser irradiation.The radial crack and the circumferential crack are generated during the laser irradiation.
Xi Wang Zewen Li Hongchao Zhang Zhonghua Shen Xiaowu Ni
School of Science,Nanjing University of Science &Technology,Nanjing 210094,China
国内会议
南京
英文
1-11
2012-06-08（万方平台首次上网日期，不代表论文的发表时间）