Patent ID: 7199421
Filing Date: 2007-04-03
Classification: G11C,H01L

Abstract:
1. A silicon-oxide-nitride-oxide-silicon (SONOS) device, comprising: a semiconductor substrate including a first surface, a second surface of lower elevation than the first surface, and a third surface perpendicular to and between the first and second surfaces; a tunnel dielectric layer disposed on the semiconductor substrate; a charge trapping layer in a form of a spacer disposed on the tunnel dielectric layer on the third surface; a charge isolation layer disposed on the tunnel dielectric layer and which covers the charge trapping layer; a gate that extends over a portion of the first surface and over a portion of the second surface and is adjacent to a portion of the third surface of the substrate on the charge isolation layer; a first impurity region formed below the first surface and near the gate, wherein the first impurity region is disposed at a distance away from the third surface and facing the charge trapping layer on the third surface; a second impurity region formed below the second surface, opposite the first impurity region; and a channel region in the semiconductor substrate between the first and second impurity regions, wherein a portion of the channel region extends along a portion of the first surface of the semiconductor substrate between the first impurity region and the third surface of the semiconductor substrate.