Methods for improving selective deposition of a capping layer on a patterned substrate are presented, the method including: receiving the patterned substrate, the patterned substrate including a conductive region and a dielectric region; forming a molecular masking layer (MML) on the dielectric region; preparing an electroless (ELESS) plating bath, where the ELESS plating bath includes: a cobalt (Co) ion source: a complexing agent: a buffer: a tungsten (W) ion source: and a reducing agent; and reacting the patterned substrate with the ELESS plating bath for an ELESS period at an ELESS temperature and an ELESS pH so that the capping layer is selectively formed on the conductive region. In some embodiments, methods further include a pH adjuster for adjusting the ELESS pH to a range of approximately 9.0 pH to 9.2 pH. In some embodiments, the pH adjuster is tetramethylammonium hydroxide (TMAH). In some embodiments, the MML is hydrophilic.