Growth dynamics and characterization of SiC quantum dots synthesized by low-frequency inductively coupled plasma assisted rf magnetron sputtering

Abstract

Self-assembled SiC quantum dots (QDs) are grown on Si substrates at a low substrate temperature of 400°C by means of low-frequency, inductively coupled plasma assisted rf magnetron sputtering from a sintered SiC target in a reactive Ar+H2 gas mixture. Effects of SiC target power and working gas pressure on the surface morphology and structural properties of SiC QDs are investigated. The growth dynamics of the QDs obeys cubic root-law behavior. With the increase of SiC target power, the growth rate increases greatly, resulting in nonuniform surface morphology and higher intensity of Si–C transmittance band. Scanning electron microscopy shows that (i) at pressure below 1Pa, SiC quantum dots are highly uniform and the average size of quantum dots increases with the increase of pressure; (ii) at pressure above 1Pa, SiC quantum dots are nonuniform, and the size of quantum dots decreases with the increase of pressure. These behaviors are explained by the scattering effects and the surface mobility of the sputtered atoms. X-ray photoelectron and Fourier transform infrared spectroscopic results show that the predominant bonds are Si–C and the elemental composition of Si and C atoms is near stoichiometric.