Influence of interfacial nitrogen on edge charge trapping at the interface of gate oxide/drain extension in metal-oxide-semiconductor transistors

In this work, the edge charge trapping at the interface of gate oxide/drain extension caused by Fowler-Nordheim injection is determined quantitatively by using a simple approach to analyze the change of the drain band-to-band tunneling current. For both pure and nitrided oxides with an oxide thickness of 6.5 nm, positive edge charge trapping is observed while the net charge trapping in the oxide above the channel is negative. It is found that the nitrogen at the interface can enhance the edge charge trapping. The results could be explained in terms of the creation of positive fixed oxide charges at the interface as a result of the electrochemical reactions involving holes and hydrogen ions. (C) 2003 American Institute of Physics.