Arrayed micro ion source with ionic liquid for flexible and concurrent MEMS fabrication

• A MEMS based micro ion source array with ionic liquid reservoir was fabricated.
• The ionic liquid was used as the ion source material.
• The emission of the ions from the ionic liquid was confirmed.
• We experimentally confirmed the physical and chemical etching by the ion emission.

This paper reports a micro ion source array (MISA) for flexible and concurrent fabrication of multiple micro devices. In this study, the ionic liquid (IL) 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM]-[BF4]) was used as the ion source material to simplify the focused ion beam (FIB) system and integrate the ion sources with high density. A reservoir for the IL was integrated into the MISA by silicon micromachining. Experimental results confirmed the emission of the ions from the [EMIM]-[BF4] and the physical etching of the metal films by the ion emission. Also, silicon fluoride volatilization could be observed by mass spectroscopy when the silicon wafer was exposed to the emitted ion beam.