Integrated atomic layer passivation in TCP etch chamber and in-situ etch-ALP method

A method for etching a substrate includes performing, in a plasma chamber, a first etch of a substrate material using a plasma etch process. The first etch forms features to a first depth in the material. Following the first etch, the method includes performing, in the plasma chamber without removing the substrate from the chamber, an atomic layer passivation (ALP) process to deposit a conformal film of passivation over the mask and the features formed during the first etch. The ALP process uses a vapor from a liquid precursor to form passivation over the features and the mask. The method further includes performing, in the plasma chamber, a second etch of the material using the plasma etch process. The conformal film of passivation is configured to protect the mask and sidewalls of the features during the second etch. A plasma processing system also is described.