Enhancement of Drain Current in Planar MOSFETs by Dopant Profile Engineering Using Nonmelt Laser Spike Annealing

We investigated the effect of dopant profile engineering in planar MOSFETs, in which activation annealing was done using only nonmelt laser spike annealing (LSA). Device performance was 10% and 20% better compared to that when conventional LSA and rapid thermal annealing (RTA) are used, respectively. We achieved this by reengineering the following: 1) angle implantation in the extension of an nFET; 2) germanium preamorphization implantation in the extension of a pFET; 3) halo implantation with lower energy and smaller tilt angle; 4) deep source/drain by two-step implantation, and 5) counter implantation adjusted to the halo conditions. Hot carrier degradation was also reduced to an RTA-comparable level by halo profile engineering. Thus, we show that a submillisecond LSA is a promising technique for the fabrication of ultrashallow junctions for the 45-nm technology node and beyond and that a dopant profile engineering taking into account the minimal diffusion length of LSA is required to bring out the best device performance.