Interface impurities of low-temperature (900 °C) deposited Si epitaxial films prepared by HF treatments

Impurities at the interfaces of HF-treated Si (100) substrates and Si films prepared by low-temperature (900 °C) chemical vapor deposition using SiH2 Cl2 were measured by secondary-ion mass spectroscopy. Si substrates were prepared by 49% HF, 5% HF, and 0.05% HF acid solutions and loaded into the growth chamber without a water rinse. Carbon, fluorine, oxygen and chlorine were detected at the interfaces for 49% HF and 0.05% HF treated substrates, but they were not detected for 5% HF-treated samples. Desorption of the contaminants appeared to be sensitively related to a difference in chemical states of the HF-treated surfaces.