SINGLE EVENT UPSET IMAGING WITH A NUCLEAR MICROPROBE

An entirely new ion beam analysis technique is described: single event upset (SEU) imaging. SEU-imaging utilizes the scanning of a micro-focused MeV ion beam across an integrated circuit. This beam generates both electrons and logic state changes which are monitored by a computer. The data is collected in a way that permits the generation of visual images which depict both the physical appearance of the scanned region (through the ion-induced electron signals) and the areas of the IC which are susceptible to upset (through detection of chip malfunctions). Comparison of these images with the chip design facilitates matching the individual transistor components with the upset-sensitive region. While our initial results with 1-mu-m resolution ion beams have demonstrated the viability of this new technique in directly identifying the sources of upset in micron-scale integrated circuits, the trend toward submicron feature size will necessitate higher-resolution microprobes and improved appearance-imaging systems in future applications of this new technique.