Methods for protecting film layers while removing hardmasks during fabrication of semiconductor devices

A method for protecting an epitaxial silicon layer of a first unmasked portion of a semiconductor substrate while removing a silicon nitride hardmask using a wet etchant from a second masked portion thereof comprising the steps of:

• providing a semiconductor substrate having a first unmasked portion and a second masked portion defined by a silicon nitride hardmask overlying the second masked portion;
• forming an epitaxial silicon layer overlying at least a portion of the first unmasked portion;
• forming a protective oxide layer overlying the epitaxial silicon layer;
• removing the silicon nitride hardmask;
• and
• removing the protective oxide layer from the epitaxial silicon layer, wherein the epitaxial silicon layer comprises a semiconductor material selected from the group consisting of silicon, silicon germanium (SiGe), silicon carbon (SiC), or a combination thereof.

A method for protecting a film layer on a semiconductor substrate against a hardmask-selective etch chemistry while removing a hardmask with the hardmask-selective etch chemistry comprising the steps of:

• providing a semiconductor substrate having a hardmask overlying at least a portion thereof defining an unmasked region and a masked region;
• carrying out a process step on the unmasked region to expose a surface of a film layer in the unmasked region;
• selectively forming a protective oxide layer overlying the film layer;
• removing the hardmask with the hardmask-selective etch chemistry;
• and
• removing the protective oxide layer.