An interconnect structure, which may be used for example in a semiconductor device, is disclosed. The interconnect structure includes a contact layer made of a metal; one or more dielectric layers on the contact layer, and a deposited layer made of an insulating material. The interconnect structure further includes a trench through the one or more dielectric layers so that a sidewall surface of the trench is formed by the one or more dielectric layers and a bottom surface of the trench is formed by a portion of the contact layer. The deposited layer is in the trench and a thickness of the insulating material on the sidewall surface of the trench is at least 2.1 times greater than a thickness of the insulating material on the bottom surface of the trench.