Strategy for focused ion beam compound material removal for circuit editing

Both selective and nonselective focused ion beam (FIB) processes have become critical for enabling fine-scale activities such as nano-machining and nano-fabrication in compound material removal applications. In this paper, we investigate the influence of FIB ion acceleration voltage on gas assisted etch rates for the most frequently used materials in the microelectronic industry, using common FIB etchants. These results can serve as a baseline for FIB process development using various materials for both highly-selective and (almost) nonselective material removal. Etching strategies are suggested. Two test cases are presented here, in which we performed either selective or nonselective material removal processes. The etch rate of different materials was found to be dependent on acceleration voltage, and very specific to the material-precursor system.