A T-gate overlapped LDD device with high circuit performance and high reliability

The authors describe a novel T-gate overlapped LDD (lightly doped drain) device having the thick gate-oxide above the LDD region. It is shown that the thick gate-oxide above the LDD region is effective in reducing the vertical electric field in the LDD region and gate-drain overlapped capacitance. The T-gate overlapped LDD structure provides low gate-induced drain leakage (GIDL) and high speed/low power dissipation. This device improves by 3.5 V the subbreakdown voltage induced by the GIDL. The 0.6- mu m T-gate overlapped LDD device provides almost the same hot-carrier resistance, and represents a circuit speed of 65 ps/stage at Vdd=3 V and 15% improvement in power dissipation when compared with the 0.6- mu m gate overlapped drain device.<>