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

A method for etching a substrate in a plasma chamber, comprising,

• receiving the substrate in the plasma chamber over a bottom electrode, the substrate having a material to be etched to form features, with a mask being provided over the substrate to define locations of the features to be etched;
• performing, in the plasma chamber, a first etch of the material using a plasma etch process, the first etch using plasma etch gases to form features to a first depth in the material;
• and
• performing, in the plasma 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 including,
• (a) introducing a vapor of a precursor including silicon into the plasma chamber to coat the mask and the features with the precursor;
• (b) generating a plasma within the plasma chamber in the presence of the precursor coated over the mask and features, the plasma generated using oxygen gas and RF power, the plasma causing the precursor to cure and form a first atomic monolayer of the conformal film of passivation;
• (c) introducing the vapor of the precursor including silicon into the plasma chamber to coat the first atomic monolayer of the conformal film of passivation with the precursor;
• and
• (d) generating a plasma within the plasma chamber in the presence of the precursor coated over first atomic monolayer, the plasma generated using the oxygen gas and the RF power, and the plasma causing the precursor to cure and form a second atomic monolayer of the conformal film of passivation,
• wherein the introducing of the vapor of the precursor and the generating of the plasma is repeated to form a third atomic monolayer or more atomic monolayers until the conformal film of passivation has a target thickness before performing a second etch of the material using the plasma etch process, the second etch using plasma etch gases to form features to a second depth in the material, the conformal film of passivation being configured to protect the mask and sidewalls of the features during the second etch.