Patent ID: 8822299

Claim:
A method of fabricating a semiconductor device, comprising: forming a gate dielectric layer comprising an oxide, and at least one conductive layer on a substrate; forming a mask on the conductive layer; patterning the at least one conductive layer by etching the at least one conductive layer using the mask as an etch mask to thereby form a gate electrode, wherein a byproduct of the etching of the at least one conductive layer comprises an oxide and is formed on the mask, and the oxide of the gate dielectric layer and a material of the at least one conductive layer are selected such that the oxide constituting the byproduct has a higher etch rate with respect to an etchant than the oxide of the gate dielectric layer; using the etchant to remove the byproduct from the mask; and subsequently conformally forming at least one capping layer on the substrate that covers the gate electrode and the mask.