Reaction of interfacial layer and trapping in HfO2 gated MOS structures

This paper presents experimental evidence of severe chemical reactions between physical-vapor-deposited (PVD) HfO₂ and the underlying SiO₂ interfacial layer, resulting in undesired trapping problems. In contrast, it will also show that HfO₂ does not react with SiN. Correspondingly, MOS capacitors made with HfO₂/SiN as the dielectric stack exhibit no trapping related problems at all. It should be noted that, the term SiN in this paper actually means SiON where the oxygen is unintentionally incorporated.