FOCUSED ION-BEAM MACHINING OF SI, GAAS, AND INP

The focused ion beam (FIB) has been demonstrated as a precision fabrication tool for a wide variety of applications, primarily for semiconductor related processing. In order to facilitate the practical utilization of this tool, the Ga+ FIB micromachining characteristics of Si (100), Si(111), GaAs (100), and InP (100) were investigated. Rectangular wells having dimensions of 4 X 10 X 1-mu-m were sputtered into the above materials at 15 and 25 keV and dwell times ranging from 25-mu-s to 100 ms per point for a fixed total machining time. Planview and cross section scanning electron microscope examination was used to quantify sputter yield and characterize feature shapes. Sputter yield and material redeposition variations dependent on beam dwell times were observed as evidenced by changes in side wall slope, crater bottom flatness, and material redeposition.