Abstract
We demonstrate the use of Raman microscopy for leak detection in hermetically sealed micromachined accelerometers. Leaks were indicated by the presence of a foreign gas, in this case oxygen, in the 70-μm-deep cavity enclosing the accelerometer between a silicon cap and a Pyrex® window. Confocal, nondiffraction-limited operation of the Raman microscope utilized the available pathlength in the sample while still rejecting most of the fluorescence from the Pyrex®. Raman peak intensities were accurately determined in the presence of noise by fitting the spectra to a function that modeled the unresolved Q-branch line shapes of oxygen and nitrogen.
Get full access to this article
View all access options for this article.
