A method for fabricating a SONOS device having a buried bit-line including the steps of: providing a semiconductor substrate having an ONO structure overlying the semiconductor substrate; forming a nitride barrier layer on the ONO structure to form, a four-layer stack; forming a patterned photoresist layer on the nitride barrier layer; implanting As or P ions through the four-layer stack to form a bit-line buried under the ONO structure; stripping the photoresist layer and cleaning an upper surface of the four-layer stack; and consolidating the four-layer stack by applying an oxidation cycle. The invention further relates to a SONOS-type device including the nitride barrier layer.