Interconnect structure and method for forming interconnect structure

Abstract

An improved interconnect structure and a method for forming the interconnect structure is disclosed that allows the interconnect structure to achieve a lower Rc. To lower the Rc of the interconnect structure, an [alpha]-phase inducing metal layer is introduced on a first Ta barrier layer of beta phase to induce the subsequent deposition of Ta thereon into the formation of an alpha-phase Ta barrier layer. The subsequently deposited Ta barrier layer with a primary crystallographic structure of alpha phase has a lower Rc than that of the beta-phase Ta barrier layer.

Description

technical field [0001] The present invention relates to interconnect structures and methods of forming them. Background technique [0002] The semiconductor integrated circuit (IC) industry has experienced rapid development. Modern integrated circuits are made of millions of active devices such as transistors and capacitors. Technological advances in IC materials and design have produced multiple generations of ICs, where each generation has smaller and more complex circuits than the previous generation. These devices are initially isolated from each other, but are then interconnected through multiple metal layers to form functional circuits. As ICs become more complex, interconnect structures also become more complex, resulting in an increase in the number of metal layers. [0003] Typical interconnect structures include lateral interconnects such as metal lines (wires) and vertical interconnects such as conductive vias and contacts. Complex interconnects can limit the ...

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Problems solved by technology

Therefore, the Ta barrier limits the overall line resistance

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