摘要 |
Etch assisting agents for focused ion beam (FIB) etching of copper for circuit editing of integrated circuits both prevent loss of adjacent dielectric due to sputtering by the ion beam, and render sputtered re-deposited copper on adjacent surfaces non-conductive to avoid electrical short circuits. The agents comprise hydrazine and hydrazine derivatives having an N—N(N being Nitrogen) bonding in their molecules and boiling points between about 70° and 220° C., and NitrosAmine derivatives saturated with two hydrocarbon groups selected from Methyl, Ethyl, Propyl and Butyl. Preferred agents are Hydrazine monohydrate (HMH), HydroxyEthylHydrazine (HEH), NDMA, NMEA, NDEA, NMPA, NEPA, NDPA, NMBA or NEBA, alone or in combination with Nitrogen Tetroxide. The agents are effective for etching copper in high aspect ratio (deep) holes. |