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The threshold voltage roll-up/roll-off characteristic control in sub-0.2-mu m single workfunction gate CMOS has been successfully achieved for high performance DRAM applications by N2 implant and well RTA optimization. It has been found that source/drain (S/D) RTA just after extension implant should be carefully and independently optimized in nFET and pFET to reduce transient enhanced diffusion (TED) during following thermal proces

Ion implantation of boron, phosphorus and arsenic into crystalline silicon is studied. Computer simulation techniques such as the multiple-interaction method and binary collision approximation are employed to quantify the implant profiles as a function of interatomic potential, electronic energy loss and target orientation effects. Both axial and planar channeling were considered for all cases.

Laser thermal processing (LTP) has been proposed as a means to avoid unwanted transient enhanced diffusion and deactivation of dopants, especially boron and arsenic, during the formation of ultrashallow junctions. Although experimental studies have been carried out to determine the efficacy of LTP for pure Si and lightly B-doped junctions, the effects of high concentrations of dopants (above 2% B) on the thermodynamic and kinetic properties of the regrown film are unknown. In this study, a classical interatomic potential model [Stillinger-Weber (SW)] is used with a nonequilibrium molecular dynamics computer simulation technique to study the laser thermal processing of heavily B-doped Si in the range 2-10 at. % B. We observe only a small effect of boron concentration on the congruent melting temperature of the B :Si alloy, and thus the narrowing of the "process window" for LTP is predicted to be small. No significant tendency for boron to segregate was observed at either the regrowth front or the buried c-Si interface during fast regrowth. The B-doped region regrew as defect-free crystal with full activation of the boron atoms at low boron concentrations (2%), in good agreement with experiments. As the concentration of boron increased, the number of intrinsic Si defects and boron interstitials in the regrown materials increased, with a minor amount of boron atoms in clusters (<2%). An instability limit for crystal regrowth was observed at around 8%-10% boron atoms during fast regrowth; systems with 10% B showed partial amorphization during regrowth. Comparison with tight-binding quantum mechanical calculations showed that the SW model gives similar diffusivities in the liquid and tendency to cluster, but the lifetimes of the SW clusters are considerably too long (> 150 ps, compared to 5 ps in tight binding). The importance of adequate system size is discussed. [ABSTRACT FROM AUTHOR]

A non-equilibrium molecular dynamics (NEMD) technique using Stillinger-Weber potentials are employed to simulate thermal processing of heavily B-doped a-Si on c-Si. The 5000 atom system provides a qualitative view of the kinetics of the laser thermal processing (LTP) systems, containing at least 20 000 atoms, provide better accuracy, and decrease fluctuations in the interfacial properties.

Discusses threshold voltage characteristic control schemes for sub 0.2-upsilonm single workfunction gate complementary metal oxide semiconductors from the viewpoint of high-performance dynamic random-access memory applications. Device fabrication and experiments; Significance of combining well RTA and nitrogen gas implant prior to gate oxidation; RTA optimization condition after source/drain implant; Impact of halo implant on threshold voltage variation.

We report the results of a theoretical analysis for the kinetics of strain relaxation in Si1-xGex thin films grown epitaxially on Si(100) substrates. The analysis is based on a properly parametrized dislocation mean-field theoretical model describing plastic deformation dynamics due to threading dislocation propagation and addresses strain relaxation kinetics during both epitaxial growth and thermal annealing, including post-implantation annealing. Theoretical predictions for strain relaxation as a function of film thickness in Si0.80Ge0.20/Si(100) samples annealed after epitaxial growth either unimplanted or after He ion implantation are in excellent agreement with experimental measurements [J. Cai et al., J. Appl. Phys. 95, 5347 (2004)]. [ABSTRACT FROM AUTHOR]