Embodiments of the present disclosure relate generally to a semiconductor device and method of fabricating the same, the semiconductor device includes a semiconductor substrate and a gate stack disposed over a channel region of the semiconductor device, the gate stack includes an oxidation layer, a gate dielectric and a gate electrode, the oxidation layer at least covers a portion of the channel region of the semiconductor device and may act as a barrier to prevent damage to the underlying features, such as the source and drain regions, during removal of a dummy gate in a gate last process.