Semiconductor device structure

A semiconductor device structure, comprising:

• a first dielectric layer over a substrate;
• a first conductive feature in the first dielectric layer;
• a second dielectric layer over the first dielectric layer and the first conductive feature;
• and
• an electrical connection structure in the second dielectric layer and on the first conductive feature, wherein the electrical connection structure includes a second conductive feature made of a first metal material and a first inhibition layer in the second conductive feature and made of a second metal material, the first metal material is different than the second metal material, an interface between the second metal material and the first metal material is lower than a top surface of the second conductive feature and spaced apart from the top surface of the second conductive feature.

A semiconductor device structure, comprising:

• a source/drain feature over a substrate;
• a contact over the source/drain feature;
• a dielectric layer over the contact;
• a via through the dielectric layer and over the contact, wherein the via comprises a plurality of grains;
• and
• an inhibition layer along grain boundaries of the grains of the via, wherein a first material of the via is different than a second material of the inhibition layer, and the inhibition layer includes a first portion laterally sandwiched between a first grain and a second grain of the plurality of grains and a second portion vertically sandwiched between the first grain and a third grain of the plurality of grains.