Fabrication and characterization of high density silicon quantum dots in gradient Si-rich carbide films

Abstract

Gradient Si -rich carbide (GSRC) thin films were deposited on monocrystalline silicon wafers and quartz substrates by magnetron co-sputtering, with subsequent thermal annealing by rapid thermal processing. Fourier transform infrared spectroscopy, Raman spectroscopy, grazing incident X-ray diffraction, transmission electron microscope, and Hall measurements were used to analyze the microstructure and conductivity of the films. It was observed that bonding configurations, microstructure and conductivity properties changes with the annealing temperature from 700°C to 1000°C. The experimental results demonstrate that Si QDs with crystal volume fraction of 72.5%, average size of 4.5 nm, and number density of ~2 ×1012 cm -2 embedded in the amorphous SiC matrix can be formed using a GSRC multilayer structure, with subsequent annealing at 1000°C. The 1000°C annealed thin film possesses a conductivity of ~5 S ⋅ cm -1, which can be attributed to high carrier transport efficiency caused by high Si QD density.