A Test Structure for Spectrum Analysis of Hot-Carrier-Induced Photoemission from Scaled MOSFETs under DC and AC Operation

A test structure with a wide channel width for analysis of hot-carrier-induced photoemission is presented and spectrum changes for 90 nm MOSFETs under DC (direct current) and AC (alternating current) operation are discussed. Comparing with DC operation, photon counts for higher photon energy increase under AC operation, and spectrum curves change with rise and fall time of gate pulse. The overshoots of drain voltage at the transition timing generate hot carriers with higher energy due to large electric field near drain region, which raise a possibility of a reliability issue related to hot carrier effects in LSIs.