Substrate etching method and system

The etching method includes etching the silicon oxide film by supplying a halogen-containing gas and a basic gas to the substrate so that the silicon oxide film is chemically reacted with the halogen-containing gas and the basic gas to generate a condensation layer; etching silicon by supplying a silicon etching gas, which includes at least one selected from the group consisting of an F2 gas, an XeF2 gas, and a ClF3 gas, to the substrate; and after the etching of the silicon oxide film and the etching of the silicon, heating and removing the condensation layer from the substrate.