A method of fabricating a memory device is described. Generally, the method includes: forming on a surface of a substrate a dielectric stack including a tunneling dielectric and a charge-trapping layer overlying the tunneling dielectric; forming a cap layer overlying the dielectric stack, wherein the cap layer comprises a multi-layer cap layer including at least a first cap layer overlying the charge-trapping layer, and a second cap layer overlying the first cap layer; patterning the cap layer and the dielectric stack to form a gate stack of a memory device; removing the second cap layer; and performing an oxidation process to oxidize the first cap layer to form a blocking oxide overlying the charge-trapping layer, wherein the oxidation process consumes the first cap layer. Other embodiments are also described.