Semiconductor devices and methods for forming semiconductor devices include opening at least one contact via through a sacrificial material down to contacts. Sides of the at least one contact via are lined by selectively depositing a barrier on the sacrificial material, the barrier extending along sidewalls of the at least one contact via from a top surface of the sacrificial material down to a bottom surface of the sacrificial material proximal to the contacts such that the contacts remain exposed. A conductive material is deposited in the at least one contact via down to the contacts to form stacked contacts having the hard mask on sides thereof. The sacrificial material is removed.