Asymmetrical halo source GOLD drain (HS-GOLD) deep sub-half micron n-MOSFET design for reliability and performance

A novel asymmetrical n-MOSFET device structure has been developed which is suitable, in terms of reliability and performance, for scaling down to the sub-quarter-micron level, without reduction of the supply voltage below 3.5 V. In this structure (HS-GOLD), large-tilt implantation is used to form the gate-overlapped lightly doped drain (GOLD) region at the drain electrode only. A halo (punch-through stopper) is used at the source, but not at the drain. Superior hot-carrier reliability and high punch-through resistance are obtained using this device structure. A reliability-limited supply voltage at 4.2 V is obtained for HS-GOLD n-MOSFETs with effective channel lengths as short as 0.25 mu m. High punch-through resistance is achieved without extreme scaling of S-D (source-drain) junctions and gate oxide (120 AA). The threshold roll-off characteristics suggest that this n-MOSFET structure can be designed with about 0.3 mu m shorter channel length (L/sub eff/=0.15 mu m) while maintaining the 3.5-V supply voltage. Reliable operation of 0.15- mu m n-MOSFETs at 3.5-V supply voltage using the proposed device structure is demonstrated by 2D simulation.<<ETX>>