Defect Control during Silicon Epitaxial Growth Using Dichlorosilane

Abstract

The incidence of hillocks and stacking faults in thick silicon epitaxial layers grown by using dichlorosilane as a source has been examined as a function of the growth parameters for the (111), (110), and (100) orientations. It was determined that the hillock and stacking fault densities decrease with increasing growth temperature and decreasing dichlorosilane flow. A continual decrease in the hillock density was observed with decreasing growth rate, without the observation of a critical growth rate above which hillocks form in the case of silicon epitaxy using silicon tetrachloride. Stacking faults were invariably found at every hillock site. For epitaxial growth performed using dichlorosilane at 1160°C with a growth rate of 1.5 microns per minute, thick epitaxial layers could be grown with hillock and stacking fault densities of less than 10/cm2 for all three surface orientations. Since this defect density is significantly lower than that observed in the silicon tetrachloride system, the dichlorosilane epitaxial growth process is more suitable for the growth of thick epitaxial layers which require relatively high growth rates.