Silicon-oxide-nitride-oxide-silicon (SONOS) devices and methods of manufacturing the same are provided. According to one aspect, a SONOS device includes a semiconductor substrate having a first surface, a second surface of lower elevation than the first surface, and a third surface perpendicular and between the first and second surfaces; a tunnel dielectric layer on the semiconductor substrate; a charge trapping layer in a form of a spacer on the tunnel dielectric layer on the third surface; a charge isolation layer on the tunnel dielectric layer, which covers the charge trapping layer; a gate that extends over a portion of the first surface, over a portion of the second surface, and is adjacent to a portion of the third surface of the semiconductor substrate on the charge isolation layer; a first impurity region formed below the first surface and near the gate; and a second impurity region formed below the second surface, opposite the first impurity region.