Copper filled contact plugs formation

The paper considers the possibility of the formation of contact plugs filled with copper instead of conventional tungsten (Fig. 1). There are increased requirements for diffusion barrier layers due to the proximity to transistor structures. Several candidate films based on TaN, TiN have been evaluated as diffusion barrier layers in terms of adhesion to copper, electrical properties, and filling contact plug. As a result, device structures with copper contact plugs have been obtained, and corresponding to the specification results have been confirmed.