A method for processing a stack with a carbon based patterned mask is provided. The stack is placed in an etch chamber. A silicon oxide layer is deposited by atomic layer deposition over the carbon based patterned mask by providing a plurality of cycles, wherein each of the cycles of the plurality of cycles, comprises providing a silicon precursor deposition phase, comprising flowing an atomic layer deposition precursor gas into the etch chamber, where the atomic layer deposition precursor gas is deposited while plasmaless and stopping the flow of the atomic layer deposition precursor gas and providing an oxygen deposition phase, comprising flowing ozone gas into the etch chamber, wherein the ozone gas binds with the deposited precursor gas while plasmaless and stopping the flow of ozone gas into the etch chamber. Part of the silicon oxide layer is etched. The stack is removed from the etch chamber.