Impact of the Metal Gate on Carrier Transport in HK/MG Transistors

We have investigated the effect of the nitrided metal gate (such as TiN or TaN) on the carrier mobility in high-k/metal gate transistors. N-induced defects are evidenced and correlated to the electron mobility degradation. Hole behavior is compared and found to differ significantly. Al integration in advanced metal gate is also found to degrade the electron mobility in a similar way as N.