US Patent 11972974 Self-aligned barrier for metal vias

An IC structure includes a transistor, a source/drain contact, a metal oxide layer, a non-metal oxide layer, a barrier structure, and a via. The transistor includes a gate structure and source/drain regions on opposite sides of the gate structure. The source/drain contact is over one of the source/drain regions. The metal oxide layer is over the source/drain contact. The non-metal oxide layer is over the metal oxide layer. The barrier structure is over the source/drain contact. The barrier structure forms a first interface with the metal oxide layer and a second interface with the non-metal oxide layer, and the second interface is laterally offset from the first interface. The via extends through the non-metal oxide layer to the barrier structure.