Effects of the Growth Rate on the Quality of 4H Silicon Carbide Films for MOSFET Applications

Abstract

In this paper we investigate the role of the growth rate (varied by changing the Si/H2ratio and using TCS to avoid Si droplet formation) on the surface roughness (Rq), the density of single Shockley stacking faults (SSSF) and 3C-inclusions (i.e. epi-stacking faults, ESF). We find that optimized processes with higher growth rates allow to improve the films inallthe considered aspects. This result, together with the reduced cost of growth processes, indicates that high growth rates should always be used to improve the overall quality of 4H-SiC homoepitaxial growths. Furthermore we analyze the connection between surface morphology and density of traps (Dit) at the SiO2/SiC interface in fabricated MOS devices finding consistent indications that higher surface roughness (step-bunched surfaces) can improve the quality of the interface by reducing theDitvalue.