Micromachined mass spectrometer

The general purpose of the present study is the realisation with silicon microtechnologies of a low cost miniature mass spectrometer working at high pressure (>1 Pa). For this, two kinds of filter have been developed in our laboratory: a quadrupole mass spectrometer and a Wien filter, which is presented in this paper. The micromachined device contains on one single chip the three main parts of a mass spectrometer: the ionisation chamber, the filter and the detector. A complete manufacturing process, based on MEMS silicon technologies, has been developed and is presented. At this stage of development, the different parts have been tested separately. Tests of the filter have been done using a macroscopic ionisation chamber. They show that such a device could be used for leak detection (helium detection). First results obtained with the micromachined ionisation chamber and the detector are also presented.