Method for manufacturing semiconductor device, method for processing substrate, and substrate processing apparatus

摘要

A processing chamber of a plasma CVD device comprises a lower electrode for placing a semiconductor substrate thereon and an upper electrode provided at a position facing the lower electrode and provided with a concave portion on a surface thereof facing a surface of the lower electrode on which the substrate is placed. In deposition process using such a processing chamber, a contaminant removal sequence is provided between a deposition processing step and an exhausting step. During the deposition process, reactive gases SiH4 and NH3 for forming a Si3N4 film are supplied together with an inert gas N2 into the processing chamber. High-frequency electric power is applied between the electrodes to discharge the reactive gases so as to form the Si3N4 film on the semiconductor substrate. During the contaminant removal sequence after the deposition processing, processing conditions are changed while the high-frequency discharge is maintained to eliminate a hollow discharge so that contaminants captured in the concave portion of the electrode are removed from the processing chamber. The processing conditions are changed by stopping the supply of the SiH4 and NH3 gases, continuing the supply of the N2 gas, and decreasing the high-frequency electric power and a processing pressure. After the processing conditions are changed, the inside of the processing chamber is exhausted to produce a high vacuum.