Silicon Oxide Film Formation by Focused Ion Beam (FIB)-Assisted Deposition

A silicon oxide film has been formed by means of 60 keV Si2+ focused ion beam (FIB)-assisted deposition. A mixture of tetramethoxysilane (Si(OCH3)4) and oxygen gases was blown onto a sample surface through a 0.2-mm-inner-diameter nozzle. A gold, silicon, and beryllium alloy source was used to produce a Si2+ ion beam in the FIB system. The beam diameter and current were 0.3 µm and 0.1 nA, respectively. The deposited film with 0.1-µm thickness and 0.7-µm width consisted mainly of silicon and oxygen, and contained scarcely any carbon. The relative ratios of silicon to oxygen atomic concentration were 1:2 near the film surface and 1:1 inside the film. The resistivity of the deposited film was 2.5 MΩcm at 5 V, and the breakdown voltage was 40 V. It was found that it would be possible to use the deposited film as an insulator for integrated circuit repair in developing semiconductor devices.