Hydrogen in MOSFETs – A primary agent of reliability issues

Hydrogen plays an important role in MOSFETS as it is intentionally introduced to passivate defects (primarily Si dangling bonds) at the Si–SiO2 interface. At the same time, hydrogen has long been known to be involved in many degradation processes, with much attention being devoted recently to bias-temperature instability (BTI). Here, we give an overview of extensive theoretical results that provide a comprehensive picture of the role that hydrogen plays in several radiation-induced degradation modes and BTI. We identify a common origin for several degradation phenomena: H is released as H+ by holes either in the oxide or in Si and is driven to the interface by a positive or negative bias, respectively, where it depassivates dangling bonds via the formation of H2 molecules. We close with a note about the role of hydrogen as a main agent for aging of microelectronics.