Methods of cutting fins, and structures formed thereby, are described. In an embodiment, a structure includes a first fin on a substrate, a second fin on the substrate, and a fin cut-fill structure disposed between the first fin and the second fin. The first fin and the second fin are longitudinally aligned. The fin cut-fill structure includes an insulating liner and a fill material on the insulating liner. The insulating liner abuts a first sidewall of the first fin and a second sidewall of the second fin. The insulating liner includes a material with a band gap greater than 5 eV.