One illustrative method disclosed herein includes, among other things, performing a first trench etching process to define an upper portion of a first fin for an NFET device and an upper portion of a second fin for a PFET device, performing a first conformal deposition process to form a conformal etch stop layer around the upper portion of both the first and second fins, with the NFET device masked, performing a second trench etching process to define a lower portion of the second fin, and performing a second conformal deposition process to form a conformal protection layer adjacent the upper portion of the second fin and on sidewalls of the lower portion of the second fin.