Abstract: A mask layer is applied to a surface of a semiconductor structure or a seed layer deposited on the surface. The mask layer has a submicron width opening with a high aspect ratio that exposes a portion of the surface or seed layer. Conductive material is conformed to the opening, for example by plating, to form a first contact on the surface or seed layer. The mask and the top layer of the semiconductor structure, except for the portion under the first contact, are removed to expose a second layer of the semiconductor structure. An insulating layer is formed along the sidewalls of the first contact and the top layer of the semiconductor structure beneath the first contact. A mask is then applied to the second layer and a second contact is formed by selectively depositing metal only on the portion of the second layer exposed by the opening.