A method and system for processing a substrate includes providing the substrate in a process chamber, the substrate having an oxide layer formed thereon, and exposing the substrate to an etching gas containing F2 gas at a first temperature to remove the oxide layer from the substrate. The substrate may subsequently be heated to a second temperature greater than the first temperature, and a film may then be formed on the substrate at the second temperature. In one embodiment, a Si film is epitaxially formed on a Si substrate.