Investigation of Sb diffusion in amorphous silicon

TL;DR

This study investigates antimony diffusion in amorphous silicon using SNMS, revealing slow mixing and estimating diffusion coefficients around 10^-21 m^2/s at 823 K, which advances understanding of diffusion processes in amorphous silicon.

Contribution

It provides experimental diffusion data for Sb in amorphous silicon and explores the effects of annealing conditions on diffusion behavior.

Findings

Diffusion coefficients are approximately 10^-21 m^2/s at 823 K.

Slow mixing observed during annealing.

Diffusion is assumed to be concentration independent.

Abstract

Amorphous silicon materials and its alloys become extensively used in some technical applications involving large area of the microelectronic and optoelectronic devices. However, the amorphous-crystalline transition, segregation and diffusion processes still have numerous unanswered questions. In this work we study the Sb diffusion into an amorphous Si film by means of Secondary Neutral Mass Spectrometry (SNMS). Amorphous Si/Si1-xSbx/Si tri-layer samples with 5 at% antimony concentration were prepared by DC magnetron sputtering onto Si substrate at room temperature. Annealing of the samples were performed at different temperature in vacuum (p<10-7 mbar) and 100 bar high purity (99.999%) Ar pressure. During annealing a rather slow mixing between the Sb-alloyed and the amorphous Si layers was observed. Supposing concentration independent diffusion, the evaluated diffusion coefficients are in the range of ~10-21 m2s-1 at 823 K.