A method of forming a semiconductor device having a vertical metal line interconnect (via) fully aligned to a first direction of a first interconnect layer and a second direction of a second interconnect layer in a selective recess region by forming a plurality of metal lines in a first dielectric layer; and recessing in a recess region first portions of the plurality of metal lines such that top surfaces of the first portions of the plurality of metal lines are below a top surface of the first dielectric layer; wherein a non-recess region includes second portions of the plurality of metal lines that are outside the recess region.

A method for forming an interconnect structure includes forming an insulating layer on a substrate. A damascene opening is formed through a thickness portion of the insulating layer. A diffusion barrier layer is formed to line the damascene opening. A conductive layer is formed overlying the diffusion barrier layer to fill the damascene opening. A carbon-containing metal oxide layer is formed on the conductive layer and the insulating layer.

A semiconductor device includes a first insulating interlayer on a substrate, metal lines in the first insulating interlayer, a first air gap between the metal lines in a first region of the substrate and a second air gap between the first insulating interlayer and at least one of the metal lines in a second region of the substrate, a liner layer covering top surfaces and side walls of the metal lines and a top surface and a side wall of the first insulating interlayer, adjacent to the first and second air gaps, and a second insulating interlayer on the liner layer and contacting the liner layer.

A method of forming a semiconductor device having a vertical metal line interconnect (via) fully aligned to a first direction of a first interconnect layer and a second direction of a second interconnect layer in a selective recess region by forming a plurality of metal lines in a first dielectric layer; and recessing in a recess region first portions of the plurality of metal lines such that top surfaces of the first portions of the plurality of metal lines are below a top surface of the first dielectric layer; wherein a non-recess region includes second portions of the plurality of metal lines that are outside the recess region.

The present application discloses a method for fabricating a semiconductor device including: providing a photomask including an opaque layer on a mask substrate and surrounding a translucent layer on the mask substrate; forming a pre-process mask layer on a device stack; patterning the pre-process mask layer using the photomask to form a patterned mask layer including a mask region corresponding to the opaque layer, a trench region corresponding to the translucent layer, and a via hole corresponding to the mask opening of via feature; performing a damascene etching process to form a via opening and a trench opening in the device stack. The device stack includes a first dielectric layer on a substrate, a first etch stop layer on the first dielectric layer, and a second dielectric layer on the first etch stop layer. The damascene etching process forms the trench opening having a bottom on the first etch stop layer.

A method of forming a semiconductor device having a vertical metal line interconnect (via) fully aligned to a first direction of a first interconnect layer and a second direction of a second interconnect layer in a selective recess region by forming a plurality of metal lines in a first dielectric layer; and recessing in a recess region first portions of the plurality of metal lines such that top surfaces of the first portions of the plurality of metal lines are below a top surface of the first dielectric layer; wherein a non-recess region includes second portions of the plurality of metal lines that are outside the recess region.

A semiconductor device includes a first insulating interlayer on a substrate, metal lines in the first insulating interlayer, a first air gap between the metal lines in a first region of the substrate and a second air gap between the first insulating interlayer and at least one of the metal lines in a second region of the substrate, a liner layer covering top surfaces and side walls of the metal lines and a top surface and a side wall of the first insulating interlayer, adjacent to the first and second air gaps, and a second insulating interlayer on the liner layer and contacting the liner layer.

A method of forming a semiconductor device having a vertical metal line interconnect (via) fully aligned to a first direction of a first interconnect layer and a second direction of a second interconnect layer in a selective recess region by forming a plurality of metal lines in a first dielectric layer; and recessing in a recess region first portions of the plurality of metal lines such that top surfaces of the first portions of the plurality of metal lines are below a top surface of the first dielectric layer; wherein a non-recess region includes second portions of the plurality of metal lines that are outside the recess region.

A substrate having thereon a first dielectric layer, a second dielectric layer, and a hard mask layer is provided. A partial via is formed in the second dielectric layer and the hard mask layer. A first photoresist pattern with a first trench opening above the partial via and a second trench opening is formed on the hard mask layer. The hard mask layer and the second dielectric layer are etched through the first trench opening and the second trench opening, thereby forming a first dual damascene structure comprising a first trench and a first via, and a second trench in the second dielectric layer, respectively. A second photoresist pattern having a self-aligned via opening above the second trench is formed. The second dielectric layer is etched through the self-aligned via opening, thereby forming a second dual damascene structure comprising the second trench and a second via under the second trench.

The present disclosure provides a method for fabricating a photomask. The method includes providing a mask substrate; forming an opaque layer on the mask substrate; pattern-writing the opaque layer to form a mask opening of trench feature in the opaque layer and expose the mask substrate; forming a translucent layer in the mask opening of trench feature to cover the mask substrate; and pattern-writing the translucent layer to form a mask opening of via feature to expose a portion of the mask substrate.