Focused-ion-beam fuse cutting for redundancy technology

Fuse cutting with focused ion beams to activate redundancy circuits is proposed, and experiments are reported that verify its potential usefulness. Aluminum fuses covered with a thin passivation layer, which are difficult to cut by conventional laser-beam technology due to the material's high reflectivity, were cut in 5 s. Ga ion beams with 30-kV acceleration voltage, 0.8- mu m beam diameter, and 0.3-A/cm/sup 2/ current density were used. No change in device properties due to focused-ion-beam irradiation was observed unless the focused ion beams were incident directly on the device. It is concluded that the focused-ion-beam programming technique will be useful for redundancy circuit programming.<
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