Patent ID: 7772637

Claim:
A semiconductor device comprising: a semiconductor substrate; a tunnel oxide layer on the semiconductor substrate; a gate structure on the tunnel oxide layer such that the tunnel oxide layer is between the gate structure and the substrate, wherein the gate structure includes a first gate electrode on the tunnel oxide layer, an inter-gate dielectric on the first gate electrode, and a second gate electrode on the inter-gate dielectric, wherein the inter-gate dielectric is between the first and second gate electrodes; a leakage barrier oxide on sidewalls of the second gate electrode, wherein a surface of the gate structure opposite the semiconductor substrate is free of the leakage barrier oxide; and an insulating spacer on the leakage barrier oxide, wherein the leakage barrier oxide is between the insulating spacer and the sidewalls of the second gate electrode, and wherein the insulating spacer and the leakage barrier oxide comprise different materials.