Chemical Engineering Communications, Vol.195, No.2, 98-114, 2008
Microfabrication of cylindrical ion trap mass spectrometer arrays for handheld chemical analyzers
A new microfabrication method for micro-cylindrical ion trap (mu-CIT) mass spectrometer arrays (r(o), z(o) congruent to 360 mu m) is presented along with a strategy for incorporating integrated high-field emission electron sources for ionization. Simulations of the performance of mu-CITs were used to guide the geometrical design of the array, and process flows for microfabrication in silicon were developed and optimized for reduced capacitance. The microfabrication process is described in detail along with initial test results. Field emission sources were also fabricated in silicon using an edge-to-edge emission strategy to improve robustness in moderate vacuum environments. Simulations were also used to guide the design of the field emitter arrays. The microfabrication process is described and initial field emission data are presented. Strategies for further optimization and integration are also briefly discussed.