A method of selectively depositing a capping layer structure on a semiconductor device structure is disclosure. The method may include; providing a partially fabricated semiconductor device structure comprising a surface including a metallic interconnect material, a metallic barrier material, and a dielectric material. The method may also include; selectively depositing a first metallic capping layer over the metallic barrier material and over the metallic interconnect material relative to the dielectric material; and selectively depositing a second metallic capping layer over the first metallic capping layer relative to the dielectric material. Semiconductor device structures including a capping layer structure are also disclosed.