Substrate processing method and substrate processing device

A substrate processing method for performing a predetermined process on a plurality of target substrates under a vacuum atmosphere using a substrate processing device that includes a plurality of processing parts for performing a substrate process on each of the plurality of target substrates, a gas supply mechanism for separately supplying gases to the plurality of processing parts, and a common exhaust mechanism for exhausting the gases inside the plurality of processing parts in a collective manner, the method comprising:

• performing a first mode in which an HF gas and an NH3 gas as processing gases are supplied to a portion of the plurality of processing parts so as to perform an etching process, and instead of the HF gas, an inert gas and/or a non-reactive gas which is not reactive with the plurality of target substrates is supplied to another portion of the plurality of processing parts so as not to perform the etching process, while controlling the common exhaust mechanism so as to exhaust the processing gases from the plurality of processing parts in a collective manner by the common exhaust mechanism;
• and
• subsequently, performing a second mode in which the HF gas and the NH3 gas as the processing gases are supplied to all of the plurality of processing parts so as to perform the etching process, while controlling the common exhaust mechanism so as to exhaust the processing gases in common from the plurality of processing parts,
• wherein, in the first mode, the supply of a mixed gas of the HF gas and the NH3 gas or a mixed gas of the inert gas and/or the non-reactive gas is performed to prevent a pressure difference from occurring between the plurality of processing parts.