Simulation and testing of a lateral, microfabricated electron-impact ion source

Simulation and experimental testing of a miniaturized, lateral, electron-impact ionization source are reported. Modeling and subsequent optimization of the device design led to a tenfold improvement in the performance of the device in comparison with earlier designs. Increased electron current contributing to ionization and increased ion collection efficiency are believed to be the main factors responsible for this improvement. SIMION software was used to model the behavior of the devices and understand the improvement in performance. The ion source can operate in a wide pressure range from 0.1 to 100 mTorr and generate ion currents in excess of 1 mu A.