Integration of Sub-melt Laser Annealing on Metal Gate CMOS Devices for Sub 50 nm Node DRAM

Abstract

We report on the integration of sub-melt laser spike annealing (LSA) on W-gate stacked DRAM. We applied the LSA as a reactivation in back-end processes to comply with the considerable metal-pattern effects and strong DRAM thermal-budget. Improvements in drive currents of peripheral transistors (4 %/14 % for n/p-FETs) are achieved by using the LSA without incurring short channel effect (SCE) while minimizing pattern effects of metal gate. DRAM cell transistors also show improvements in drive current, junction leakage, and GIDL (gate-induced drain leakage) without laser-induced local defects and reliability degradation