Focused-ion-beam-induced insulator deposition at decreased beam current density

Localized focused-ion-beam (FIB) induced deposition of an insulating film provides reconstructive capability in previously modified areas. The application of this technique has led to a need for an ion-induced deposited insulator material with improved dielectric integrity. This paper presents a method that increases the yield of FIB-deposited SiO₂ films per incident ion by decreasing the current density of the ion beam. Both electrical and chemical analyses are presented of films deposited with a range of beam current densities and pixel sizes. As predicted, as the current density is decreased, the deposition yield increases. An incremental decrease in the atomic percent of gallium is detected in the films deposited at lower current densities, while the atomic percent of oxygen increases slightly and the atomic percent of silicon remains approximately unchanged. No degradation or enhancement of the films electrical integrity, as measured by leakage current, is achieved by reducing the current density by as much as a factor of ten from that of a standard process for a commercial focused-ion-beam system