A new soft-error phenomenon in VLSIs: the alpha-particle-induced source/drain penetration (ALPEN) effect

The alpha-particle source/drain penetration (ALPEN) effect is investigated using a 3-D device simulator (CADDETH) and a novel experimental method. A study of soft error due to alpha-particle injection has so far focused on such memory structures and circuits as DRAMs/SRAMs. However, a new soft error is expected to occur in single MOSFETs as the effective channel length becomes comparable to the funneling length. The authors describe: (1) the funneling penetration current between source and drain; (2) a new soft error (0→1) caused by the ALPEN effect; (3) experimental verification of the ALPEN effect; and (4) the impact on VLSI scaling. The ALPEN effect puts various constraints, such as the latch-up, emitter-to-collector short in bipolars, and punchthrough in parasitic MOSFETs, on VLSI design. Thus, the ALPEN effect will be a crucial factor in the scaling limits of future ULSIs with dimensions below 0.5 μm