Firstly, the progress made towards the formation of ultra-shallow junctions with the help of advanced annealing techniques, low-energy implants, and GCIB doping is presented. The experimental results obtained with flash annealing indicate that it is possible to achieve sub-15 nm junctions with lower sheet resistance (~1000 Omega/sq.), adequate for 32 nm CMOS technology. Since high-k/metal-gate stacks are already used in the most advanced 45 nm CMOS technology today, it is important to assess the compatibility of flash annealing with high-k/metal-gate stacks. The process integration of high-k/metal-gate stacks with flash annealing is discussed next. It is shown that the flash annealing process has minimal effects on gate stack properties and is found to be compatible with the high-k/metal-gate stacks. However, it results in degraded interface quality which is improved by using a post-metallization anneal.
To reduce the effective SBH of silicide-to-semiconductor contact, various species (nitrogen, fluorine, sulfur and selenium) are studied. These species were implanted into the semiconductor, and then piled up at the silicide-semiconductor interface during the silicidation process. It is shown that significant SBH lowering (by as much as 0.37 eV) can be achieved on n-type silicon using nitrogen. The impact of this process on the properties of NiSi is assessed and the mechanism of SBH reduction is explained. Encouraging results are also obtained with sulfur and selenium, and a comparison of effective SBH reduction is made for all studied species. Finally, material properties of nickel germanide formed on epi-Ge on Si substrate are studied to form low-resistance and thermally stable contact material for realizing highly-scaled high-performance technology based on Ge-channel MOSFETs.