Abnormal junction profile of submicrometer complementary metal oxide semiconductor devices with Co silicidation and shallow trench isolation processes

Transmission electron microscopy (TEM) combined with selective chemical etching has been performed to investigate the leakage mechanism in n-type metal oxide semiconductors (nMOS) fabricated using Co silicidation and shallow trench isolation processes. TEM and TSUPREM-4 simulated results show that dopant profiles bend upward near the interface between the active region and the field oxide. Based on the TEM and simulation results, it is suggested that a shallower junction formed near the active edge could serve as a source for leakage current in the nMOS.