Silicon wafers as obtained from the manufacturer are immersed in a large area argon/hydrogen plasma for surface cleaning. The plasma discharge is maintained between a heated cathode and the grounded process chamber at discharge voltages of about 30 V for which discharge currents up to 100 A can be chosen. In this regime, neither the chamber walls nor the substrates are sputtered. Chemical reactions at the wafer surface are assumed to be mainly stimulated by low energy electron bombardment. The etch rates for diamond-like carbon (DLC) on silicon wafers were determined for selected discharge parameters and compared with the previously obtained results for SiO2. It was found that 5 minutes in-situ cleaning prepares the silicon wafers for homoepitaxy at 500 °C and higher substrate temperatures, whereas a short anneal at 500 °C was necessary to obtain low temperature homoepitaxy at 300 °C on (100) and 400 °C on (111) silicon. This seems to be due to hydrogen passivation of silicon during the cleaning procedure.