Atomistic Study on Dopant-Distributions in Realistically Sized, Highly P-Doped Si Nanowires

作者：Ryu Hoon^*; Kim Jongseob; Hong Ki Ha

来源：Nano Letters, 2015, 15(1): 450-456.

DOI：10.1021/nl503770z

• Highly doped nanostructures
• P-doped Si nanowires
• dopant-distributions
• atomistic modeling
• Schrodinger-Poisson simulations

The dependency of dopant-distributions on channel diameters in realistically sized, highly phosphorus-doped silicon nanowires is investigated with an atomistic tight-binding approach coupled to self-consistent SchrodingerPoisson simulations. By overcoming the limit in channel sizes and doping densities of previous studies, this work examines electronic structures and electrostatics of free-standing circular silicon nanowires that are phosphorus-doped with a high density of similar to 2 x 10(19) cm(3) and have 12 nm-28 nm cross-sections. Results of analysis on the channel energy indicate that the uniformly distributed dopant profile would be hardly obtained when the nanowire cross-section is smaller than 20 nm. Insufficient room to screen donor ions and shallower impurity bands are the primary reasons of the nonuniform dopant-distributions in smaller nanowires. Being firmly connected to the recent experimental study (Proc. Natl. Acad. Sci. U.S.A. 2009, 106, 1525415258), this work establishes the first theoretical framework for understanding dopant-distributions in over-10 nm highly doped silicon nanowires.

• 出版日期2015-1