New method for testing hermeticity of silicon sensor structures

Abstract A method for testing the 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 has been evaluated by measuring a test silicon cavity filled with a controlled amount of test gas. N 2 O is evaluated as the test gas in this experiment.