Faceted anomalous scaling in the epitaxial growth of semiconductor films

TL;DR

This study applies the generic dynamical scaling theory to analyze the surface morphology of CdTe semiconductor films, revealing faceted structures and highlighting the impact of measurement resolution on surface characterization.

Contribution

The paper demonstrates the application of GDST to semiconductor film surfaces and explains discrepancies caused by probe tip convolution effects.

Findings

GDST predicts faceted morphology contrary to local roughness analysis.

Finite probe tip size affects surface roughness measurements.

High-resolution AFM confirms GDST-based predictions.

Abstract

We apply the generic dynamical scaling theory (GDST) to the surfaces of CdTe polycrystalline films grown in glass substrates. The analysed data were obtained with a stylus profiler with an estimated resolution lateral resolution of $l_c=0.3 \mu$m. Both real two-point correlation function and power spectrum analyses were done. We found that the GDST applied to the surface power spectra foresees faceted morphology in contrast with the self-affine surface indicated by the local roughness exponent found via the height-height correlation function. This inconsistency is explained in terms of convolution effects resulting from the finite size of the probe tip used to scan the surfaces. High resolution AFM images corroborates the predictions of GDST.