A Novel Ion Source and Detector for a Miniature Mass Spectrometer

Due to its flexibility and sensitivity, mass spectrometry is a preferred sensing method for applications ranging from explosives detection to air quality monitoring. The key functional elements of a mass spectrometer are ionization, mass separation, and ion detection. This work describes the development of two enabling technologies for the realization of a miniature mass spectrometer -an on-chip electron impact ion source and a micro Faraday cup array for ion detection. The small, power efficient ion source based on field emission of carbon nanotubes is the first reported lateral on-chip ion source using a cold cathode. The detector array is a linear array of Faraday cups created with a novel fabrication process that allows for much shorter cup spacing than previously achieved. When combined with a static magnetic field for ion separation, these components will enable a miniature, power efficient mass spectrometer.