Film Morphology and Process Conditions in Epitaxial Silicon Carbide Growth via Chlorides Route

Abstract

A simplified deposition model, involving both the description of the deposition and of the film morphology was adopted to quantitatively understand the experimental trends encountered in the epitaxial silicon carbide deposition in an industrial hot wall reactor. The attention was focused on the system involving chlorinated species because its really superior performances with respect the traditional silane/hydrocarbons process. The evolution of the crystalline structure (i.e., from poly to single) and of the surface roughness can be understood by simply comparing two characteristic times, like those inherent the surface diffusion and the matter supply to the surface.

Thick homoepitaxial layers grown on on-axis Si-face 6H- and 4H-SiC substrates with HCl addition

“…Consequently much more silicon atoms reach the epilayer so that the true C/Si ratio on the surface is lower than when not adding chlorine. This is not in accordance with what is reported by a simulation study of Masi et al [23] where a higher Cl/Si ratio is stipulated to produce a higher C/Si ratio on the surface but no experimental results were made to confirm this prediction. In contradiction, experimental results from Pedersen et al [35] show that by increasing the Cl/Si ratio the N-type doping is favoured, which also appears to be the case in the present study.…”

“…There are several references that may be found in literature about thermodynamic and kinetic simulations on the growth of SiC using standard precursors [22] or chlorinated chemistry [23,24].…”

High Growth Rate of 4H-SiC Epilayers on On-Axis Substrates with Different Chlorinated Precursors

“…This experimental evidence is in agreement with a theoretical study by Masi et al where a higher C/Si ratio was stipulated to be formed on the surface by using high Cl/Si ratios. 25 In fact, C-rich conditions both favor the 3C polytype formation 8 and decrease nitrogen incorporation. 23 Besides, higher Cl/Si ratios led to higher growth rates, which made it more critical to maintain a stable homopolytypic growth, as showed in another configuration.…”

Chloride-Based CVD Growth of Silicon Carbide for Electronic Applications

“…Simulations of chloride-based SiC CVD processes have mainly been focused on describing the differences in gas chemistry and growth rate, induced by the addition of chlorine. Numerical modeling has been done on chloride-based CVD with the HCl approach, − with the SiH x Cl y approach with SiHCl 3 , ,− and with SiCl 4 for bulk growth using HCVD described above ,,− and for bulk growth using the HTCVD method, and the CH x Cl y approach has been modeled for CH 3 Cl . These reports show the clear difference in gas phase composition for the chloride-based CVD process as compared to the standard SiC CVD process; the most important Si species in the gas phase is SiCl 2 instead of SiH 2 .…”