Analysis of cracking in brittle substrate

Cracking of a brittle substrate, which is a silicon substrate containing a diaphragm, was studied. Fracture patterns and surfaces were analyzed using optical microscope, infrared microscope and scanning electron microscope. Stress analysis of the substrate was carried out to understand the deformation of the silicon diaphragm as it is subjected to uniform pressure. Mechanical testing of the silicon material was conducted to further understand the crack propagation behavior of the substrate. A failure mechanism was proposed and discussed based on the experimental and theoretical analyses.