Abstract: The present disclosure describes an exemplary method that can prevent or reduce out-diffusion of Cu from interconnect layers to magnetic tunnel junction (MTJ) structures. The method includes forming an interconnect layer over a substrate that includes an interlayer dielectric stack with openings therein; disposing a metal in the openings to form corresponding conductive structures; and selectively depositing a diffusion barrier layer on the metal. In the method, selectively depositing the diffusion barrier layer includes pre-treating the surface of the metal; disposing a precursor to selectively form a partially-decomposed precursor layer on the metal; and exposing the partially-decomposed precursor layer to a plasma to form the diffusion barrier layer. The method further includes forming an MTJ structure on the interconnect layer over the diffusion barrier layer, where the bottom electrode of the MTJ structure is aligned to the diffusion barrier layer.

Abstract: In a method for manufacturing a semiconductor device, a substrate is provided. Various first metal layers are formed on the substrate. A dielectric structure with through holes is formed over the first metal layers. The through holes expose the first metal layers. A pre-clean operation is performed on the dielectric structure and the first metal layers by using an alcohol base vapor and/or an aldehyde base vapor as a reduction agent. Conductors are formed on the first metal layers. In forming the conductors, the through holes are filled with the conductors.

Abstract: A via structure, a MRAM device using the via structure and a method for fabricating the MRAM device are provided. In the method for fabricating the MRAM device, at first, a first dielectric layer is deposited over a transistor. Then, a contact is formed in the first dielectric layer and electrically connected to the transistor. Thereafter, a metal nitride layer is deposited over the first dielectric layer and the contact. Then, an etch stop layer is deposited over the metal nitride layer. Thereafter, a second dielectric layer is deposited over the etch stop layer. Then, a via structure is formed in the second dielectric layer, the etch stop layer, and the metal nitride layer and landing on the contact. Thereafter, a memory stack is formed over the via structure.