# Cluster-Assisted Mesoplasma Chemical Vapor Deposition for Fast Epitaxial Growth of SiGe/Si Heterostructures: A Molecular Dynamics Simulation Study

## TL;DR

This study uses molecular dynamics simulations to explore how SiGe nanoclusters can help grow high-quality SiGe/Si heterostructures quickly using a special deposition method.

## Contribution

The study introduces a cluster-assisted mesoplasma CVD method for fast epitaxial growth of SiGe/Si heterostructures using molecular dynamics simulations.

## Key findings

- Mixed SiGe nanoclusters enhance epitaxial growth due to their loosely bound atomic structures and high mobility.
- Smaller clusters and higher substrate temperatures lead to faster structural ordering and smoother surfaces.
- Cluster-assisted deposition achieves epitaxial bridging during impingement, with consistent SiGe composition.

## Abstract

Co-condensation of mixed SiGe nanoclusters and impingement of SiGe nanoclusters on a Si substrate were applied using molecular dynamics (MD) simulation in this study to mimic the fast epitaxial growth of SiGe/Si heterostructures under mesoplasma chemical vapor deposition (CVD) conditions. The condensation dynamics and properties of the SiGe nanoclusters during the simulations were investigated first, and then the impingement of transient SiGe nanoclusters on both Si smooth and trench substrate surfaces under varying conditions was studied theoretically. The results show that the mixed nanoclusters as precursors demonstrate potential for enhancing epitaxial SiGe film growth at a high growth rate, owing to their loosely bound atomic structures and high mobility on the substrate surface. By varying cluster sizes and substrate temperatures, this study also reveals that smaller clusters and higher substrate temperatures contribute to faster structural ordering and smoother surface morphologies. Furthermore, the formed layers display a consistent SiGe composition, closely aligning with nominal values, and the cluster-assisted deposition method achieves the epitaxial bridging of heterostructures during cluster impingement, highlighting its additional distinctive characteristics. The implications of this work make it clear that the mechanism of fast alloyed epitaxial film growth by cluster-assisted mesoplasma CVD is critical for extending it as a versatile platform for synthesizing various epitaxial films.