Patent ID: 8703003

Claim:
A method of vapor etching a sample comprised of a first layer atop of and in contact with a second layer which is atop of and in contact with a third layer, wherein at least the first and second layers are comprised of different materials, the method comprising: (a) causing the sample to be etched by a first vapor etchant in a main chamber under first process conditions that cause at least a part of the first layer to be fully removed while leaving the third layer and the second layer underlying the removed part of the first layer substantially unetched; and (b) causing the sample to be etched by a second vapor etchant in the main chamber under second process conditions that cause at least the part of the second layer exposed by the removal of the at least part of the first layer in step (a) to be fully removed while leaving the third layer underlying the removed part of the second layer substantially unetched; wherein the first layer comprises a material that is readily etched by XeF 2 ,KrF 2 , or BrF 3 , the second layer comprises a transitional metal, a nitride of a transitional metal, or an alloy of a transitional metal, and the third layer comprises a dielectric.