Investigation of 3D microfabrication characteristics by focused ion beam technology in silicon

Combining with experimental milling, 3D microfabrication by FIB technology has been studied. The relationship among limiting aperture size, dwell time, retrace time, tail of Gaussian distribution, etc. have been analyzed in terms of experimental results. Some phenomena are explained from the theoretical point of view. In addition, the influence of redeposition for the sidewall root of the microstructure in the process of milling is analyzed, and the avoiding methods for its avoidance are determined. It was established by experiment that beam current (representing ion beam energy), and spot size (FWHM represents the profile of Gaussian distribution) play an important role in the etching process. Nonlinear variation of these parameters led to the broadening of the edge periphery and redeposition at the root of the sidewall.