Low-damage specimen preparation technique for transmission electron microscopy using iodine gas-assisted focused ion beam milling

A novel method is presented for the preparation of high-resolution electron microscopy specimens with gas-assisted focused ion beam (FIB) milling. An etching rate of InP is enhanced 11–13 times with iodine gas-assisted FIB milling, compared to conventional FIB milling. Specimens with lower radiation damage can be prepared due to lower ion dose during FIB milling, and show no anomalous contrast which comes from the artifacts during FIB milling. Damaged layer introduced during FIB milling was also investigated.