Experimental and simulated P and As dopant diffusion profiles in Si:C epi films containing high C (>1 atomic %) are presented. A new set of physical effects were incorporated to accurately model P or As diffusion in the presence of high level of C. Evolution of substitutional C (Csub) profile in the Si:C epi film through dopant implant and activation anneal was characterized by high-resolution x-ray diffraction (HRXRD) technique. Three-layer analysis was utilized to obtain non-uniform Csub profile. Dependency of Csub retention on anneal thermal budget is studied. It is shown the initial Csub in the epi layer is lost during dopant implantation and conventional spike anneal sequence. Use of advanced millisecond (ms) laser anneal resulted in near 100% Csub retention in P-implanted Si:C epi film without compromising junction depth. Measured Csub (by HRXRD) and total C (by SIMS) profiles are compared with the ones predicted by the newly developed compact modeling in this study.

The advantages of fluorine co-implantation on reducing the deep P junction profile is investigated and commented as a possible valuable solution for further scaling of the NMOS transistors spacer length. On PMOS transistors, Ge+C+B cocktail junctions lead to improved short channel effects control, S/D resistance and performance over the conventional approaches. Additional laser annealing induces a partial dissolution of the doping clusters in the junction and lower the S/D transistors resistance. A performance improvement is demonstrated both for NMOS and PMOS with cocktail junctions activated by spike RTA and additional laser annealing.

As extensions have been up till now always used in N-MOS transistors with an activation anneal. Here, we show that also alternative doping by P can result in junction extensions that are extremely abrupt and shallow thus suitable for upcoming transistor technologies. P extensions are manufactured by amorphization, carbon co-implantation and conventional rapid thermal annealing (RTA). The impact of Si interstitials (Sii) flux suppression on the formation of P junction extensions during RTA is demonstrated. We have concluded that optimization of implants followed by RTA spike offers excellent extensions with depth Xj = 20 nm (taken at 5 × 1018 at./cm3), abruptness 3 nm/dec. and Rs = 326 Ω. Successful implementation of these junctions is straightforward for N-MOS devices with 30 nm gate length and results in an improved short channel effects with respect to the As reference.

We present B junction extensions that are extremely abrupt and shallow manufactured by amorphization, C co-implantation and conventional rapid thermal annealing (RTA). Resulting junctions have abruptnesses of 2 nm/dec better than as-implanted profiles. The most shallow B junction that has been manufactured is 15 nm deep and Rs = 626 Ω/sq. Successful implementation of these junctions is straightforward for P-MOS 30 nm gate length devices.