Change in Microroughness of a Silicon Surface during In Situ Cleaning Using HF and HCl Gases

The change in microroughness of a silicon substrate surface is studied at each step of an in situ cleaning method performed entirely in a hydrogen ambient at atmospheric pressure, which comprises the removal of native oxide film using hydrogen fluoride gas and the removal of an organic hydrocarbon film using hydrogen chloride gas. The root-mean-square average roughness and the power spectral density show that no surface roughening is caused by this in situ cleaning method. Additionally, it is shown in this study that heat-treatment at 1223 K in a hydrogen ambient at atmospheric pressure can smooth the silicon substrate surface when the surface is bare. The effect of the removal of an organic hydrocarbon film using hydrogen chloride gas on the morphology of the silicon substrate surface is also studied.