A new fabrication process for an electrolessly deposited NiReP barrier layer on SiO2 is proposed for ultralarge scale integration applications. The NiReP film was formed electrolessly without sputtered seeds by utilizing a self-assembled monolayer (SAM) as an adhesion and catalyst layer. For the electroless deposition on the SiO2 layer covered with SAM, an acid or a neutral electroless deposition bath was suitable whereas an alkaline solution damaged the SiO2 surface. To fabricate a consistently uniform barrier film on the SAM/SiO2 surface, a two-step process, consisting of a nucleation step performed in an acid electroless deposition bath and a barrier layer formation step carried out in an alkaline bath, is proposed. The two-step process yielded satisfactory results, and the electroless NiReP barrier layer was successfully formed on the SAM/SiO2 surface in a high pH bath.