A metal interconnect structure is doped with zinc, indium, or gallium using top-down doping processes to improve diffusion barrier properties with minimal impact on line resistance. Dopant is introduced prior to metallization or after metallization. Dopant may be introduced by chemical vapor deposition on a liner layer at an elevated temperature prior to metallization, by chemical vapor deposition on a metal feature at an elevated temperature after metallization, or by electroless deposition on a copper feature after metallization. Application of elevated temperatures causes the metal interconnect structure to be doped and form a self-formed barrier layer or strengthen an existing diffusion barrier layer.

The present application discloses a semiconductor device with a composite barrier structure and a method for fabricating the semiconductor device. The semiconductor device includes a substrate; a first dielectric layer having a feature opening on a substrate; a composite barrier structure in the feature opening, wherein the composite barrier structure includes a barrier layer in the feature opening and an assisting blocking layer on the barrier layer; and a conductive feature on the assisting blocking layer; wherein the barrier layer comprises tantalum, and the assisting blocking layer comprises copper manganese alloy.

A semiconductor device includes a lower structure including a substrate and a cell structure on the substrate and a plurality of interconnection layers, which are stacked on the lower structure in a first direction extending perpendicular to a top surface of the substrate. An uppermost interconnection layer of the plurality of interconnection layers includes uppermost conductive lines. Each of the uppermost conductive lines includes a lower metal compound pattern, a metal pattern, an upper metal compound pattern, and a capping pattern, which are sequentially stacked in the first direction. The lower metal compound pattern, the metal pattern, and the upper metal compound pattern include a same metallic element.

A device includes a dielectric layer and a conductor in the dielectric layer including a first conductive material. A conductive liner wraps around the conductor and includes a second conductive material. A barrier layer is at an interface between the conductive liner and the dielectric layer, including a first oxide and a second oxide.

A metal interconnect structure is doped with zinc, indium, or gallium using top-down doping processes to improve diffusion barrier properties with minimal impact on line resistance. Dopant is introduced prior to metallization or after metallization. Dopant may be introduced by chemical vapor deposition on a liner layer at an elevated temperature prior to metallization, by chemical vapor deposition on a metal feature at an elevated temperature after metallization, or by electroless deposition on a copper feature after metallization. Application of elevated temperatures causes the metal interconnect structure to be doped and form a self-formed barrier layer or strengthen an existing diffusion barrier layer.

A method of manufacturing a radio frequency switch includes the steps of: forming a first silicide layer on a second conductive or semiconductor layer; forming a third insulating layer on the first layer; forming a cavity in the third insulating layer reaching the first silicide layer; forming a fourth metal layer in the cavity in contact with the first silicide layer; performing a non-oxidizing annealing; and filling the cavity with a conductive material. The first silicide layer is provided on one or more of the gate, source, and drain of a transistor forming the radio frequency switch.