New Method For Testing Hermeticity Of Silicon Sensor Structures

A method for testing hermeticity of different wafer bonding processes used in silicon sensor devices is proposed. The method is based on measuring the gas concentration in a sealed silicon cavity by Fourier Transform Infrared spectroscopy (FTIR). The gas concentration and thereby the leakage into the sealed silicon cavity after external pressure exposure is measured by FTIR-absorbance. In this work the method was evaluated by measuring a test silicon cavity filled with a controlled amount of test gas. N/sub 2/O as testing gas was evaluated in this experiment.