A PECVD CNT-based open architecture field ionizer for portable mass spectrometry

This paper reports a novel carbon nanotube (CNT)- based field ionizer that is part of a portable micro gas analyzer. The device uses a micro-fabricated 3D foam-like silicon structure (mufoam) to increase the neutral particle flux, resulting in higher ion current. The mufoam is fabricated using deep reactive ion etching (DRIE). The ionizer uses plasma enhanced chemical vapor deposited (PECVD) CNTs as field enhancers. The PECVD CNT growth interacts with the mufoam to produce a sparse array of isolated CNT clusters on top of the mufoam. Electrical tests of the device both as an electron field emitter and field ionizer are reported and discussed.