A method of forming a semiconductor structure includes forming two or more pillar structures over a top surface of a substrate. The method also includes forming two or more contacts to the two or more pillar structures. The method further includes forming an insulator between the two or more pillar structures and the two or more contacts. The two or more contacts are self-aligned to the two or more pillar structures by forming the insulator via conformal deposition and etching the insulator selective to a spin-on material formed over the insulator between the two or more pillar structures.