Comparison of arsenic diffusion in Si1-xGex formed by epitaxy and Ge+ implantation

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Description/Abstract

A comparison is made of arsenic diffusion in Si0.95Ge0.05 produced by epitaxy and ion beam synthesis using a 2 x 1016cm-2Ge+ implant into silicon. The arsenic diffusion depth at 1025 degrees c in the Si0.95Ge0.05 epitaxy sample is enhnaced by a factor of 1.26 compared with a similar Si control sample and by a factor of 1.30 in the ion beam synthesized sample. The arsenic diffusion in the Si0.95 Ge0.05 epitaxy sample is modeled by increasing the arsenic diffusion coefficient from the Si value of 1.92 x 10-15 to 5.15x10-15cm2s-1, and in the ion beam synthesized sample by using the same diffusion coefficient of 5.15x10-15cm2s-1 and increasing the "plus one" factor in the transient enhanced diffusion model from 0.01 to 1.5. Arsenic diffusion in a silicon sample implanted with 2x1015cm-2Si+ can be modeled using the same plus one factor of 1.5, thereby demonstrating the consistency of the modeling.