This paper reports the nitridation effects on 1/f noise in n-MOSFETs with MOCVD HfO 2 as gate dielectric. Nitridation of the gate oxides was carried out by using a post-deposition anneal (PDA) process in a N 2 or NH 3 ambient. Predominantly 1/f type noise is observed, with γ∼1. For non-nitrided interfaces, significant variation in noise was observed when different PDAs are employed. Among the studied PDAs, devices annealed with N 2 show the lowest input referred noise, close to ITRS specifications when compared to O 2 and NH 3 anneals. Decoupled plasma nitridation (DPN) with 7-9% N 2 content was employed for devices involving nitrided interfaces. Post-deposition anneals on such devices showed a suppressed effect as the input-referred noise was found to have similar values for the different conditions. The noise mechanism is also found to vary in devices with nitrided interface and no-PDA. A significant change in trap profile is noticed between nitrided and non-nitrided interfaces, which may be one of the causes for the differences observed. Lower trap densities are obtained from the trap profile for the non-nitrided no-anneal condition. Volume and interface trap densities, extracted from input-referred noise values, showed lowest values for a N 2 PDA anneal, while an O 2 anneal showed the highest values for non-nitrided devices. Devices with nitrided interfaces show similar value for all PDAs, with the values in-between the N 2 and the O 2 non-nitrided PDA. copyright The Electrochemical Society.
|Original language||English (US)|
|Number of pages||11|
|State||Published - Dec 1 2005|
|Event||3rd International Symposium on High Dielectric Constant Gate Stacks - 208th Meeting of the Electrochemical Society - Los Angeles, CA, United States|
Duration: Oct 16 2005 → Oct 21 2005
All Science Journal Classification (ASJC) codes