Methods for forming microelectronic device structures include forming interconnects that are self-aligned with both a lower conductive structure and an upper conductive structure. At least one lateral dimension of an interconnect is defined upon subtractively patterning the lower conductive structure along with a first sacrificial material. At least one other lateral dimension of the interconnect is defined by patterning a second sacrificial material or by an opening formed in a dielectric material through which the interconnect will extend. A portion of the first sacrificial material, exposed within the opening through the dielectric material, along with the second sacrificial material are removed and replaced with conductive material(s) to integrally form the interconnect and the upper conductive structure. The interconnect occupies a volume between vertically overlapping areas of the lower conductive structure and the upper conductive structure, where such overlapping areas coincide with the opening through the dielectric material.

Methods and structures provide horizontal conductive lines of fine pitch and self-aligned contacts extending from them, where the contacts have at least one dimension with a more relaxed pitch. Buried hard mask materials permit self-alignment of the lines and contacts without a critical mask, such as for word-line electrode lines and word-line contacts in a memory device.

A method includes forming a carbon-containing layer with a carbon atomic percentage greater than about 25 percent over a first hard mask layer, forming a capping layer over the carbon-containing layer, forming a first photo resist over the capping layer, and etching the capping layer and the carbon-containing layer using the first photo resist as a first etching mask. The first photo resist is then removed. A second photo resist is formed over the capping layer. The capping layer and the carbon-containing layer are etched using the second photo resist as a second etching mask. The second photo resist is removed. A third photo resist under the carbon-containing layer is etched using the carbon-containing layer as etching mask. A dielectric layer underlying the third photo resist is etched to form via openings using the third photo resist as etching mask. The via openings are filled with a conductive material.

A method for manufacturing an interconnection structure for an integrated circuit is provided. The integrated circuit includes a first insulating layer, a second insulating layer, and a third insulating layer. Electrical contacts pass through the first insulating layer, and a component having an electrical contact region is located in the second insulating layer. The method includes etching a first opening in the third layer, vertically aligned with the contact region. A fourth insulating layer is deposited to fill in the opening, and a second opening is etched to the contact region by passing through the opening in the third insulating layer. A metal level is formed by filling in the second opening with a metal.

Apparatuses and methods to provide a fully self-aligned via are described. Some embodiments of the disclosure utilize a cap layer to protect an insulating layer in order to minimize bowing of the side walls during metal recess in a fully self-aligned via. The cap layer can be selectively removed, thus increasing the aspect ratio, by exposing the substrate to a hot phosphoric acid solution.

A method for fabricating a semiconductor device comprises: providing a substrate having a top surface; forming a bottom metal embedded in the substrate; forming a first etch stop layer, a first dielectric layer, a second etch stop layer and a second dielectric layer sequentially stacked on the top surface of the substrate; forming a semiconductor element disposed on the first etch stop layer, wherein the semiconductor element comprises a top plate and an etch stop pad disposed on the top plate; performing a first etching process to form a first partial via and a second partial via penetrating the second dielectric layer, the second etch stop layer and a portion of the first dielectric layer, wherein the first partial via is separated from the bottom metal by the first dielectric layer, and the second partial via is separated from the top plate by the etch stop pad.

A method for fabricating a semiconductor device comprises: providing a substrate having a top surface; forming a bottom metal embedded in the substrate; forming a first etch stop layer, a first dielectric layer, a second etch stop layer and a second dielectric layer sequentially stacked on the top surface of the substrate; forming a semiconductor element disposed on the first etch stop layer, wherein the semiconductor element comprises a top plate and an etch stop pad disposed on the top plate; performing a first etching process to form a first partial via and a second partial via penetrating the second dielectric layer, the second etch stop layer and a portion of the first dielectric layer, wherein the first partial via is separated from the bottom metal by the first dielectric layer, and the second partial via is separated from the top plate by the etch stop pad.

The present disclosure provides a semiconductor device. The semiconductor device includes a substrate having a first conductive pattern and a conductive mask disposed over the first conductive pattern. The semiconductor device further includes a second conductive pattern disposed over the conductive mask, and electrically connecting with the first conductive pattern through the conductive mask. The conductive mask has a lower etch rate to a predetermined etchant than the second conductive pattern. A method for forming the semiconductor device is also provided.

An interconnect structure and a method of forming an interconnect structure are disclosed. The interconnect structure includes a lower etch stop layer (ESL); an upper low-k (LK) dielectric layer over the lower ESL; a first conductive feature in the upper LK dielectric layer, wherein the first conductive feature has a first metal line and a dummy via contiguous with the first metal line, the dummy via extending through the lower ESL; a first gap along an interface of the first conductive feature and the upper LK dielectric layer; and an upper ESL over the upper LK dielectric layer, the first conductive feature, and the first gap.

A method of forming an interconnection structure includes following steps. A dielectric structure is deposited over a non-insulator structure. The dielectric structure is etched to form a via opening. A mask layer is formed over the dielectric structure. The mask layer is patterned. An anti-adhesion layer is deposited on a sidewall of the via opening after patterning the mask layer. The dielectric structure is etched to form a trench opening, wherein the patterned mask layer is used as an etch mask during forming the trench opening. A conductive structure is formed in the via opening and the trench opening.