Method of Forming Interconnect Structure

Abstract

An interconnection structure forming method comprises the steps that a substrate is provided, an opening is formed in the substrate, a conductive layer in the substrate is exposed through the opening, and a first treatment is conducted on the opening by using first plasma. First plasma gas comprises carbon monoxide. A second treatment is conducted on the opening by using second plasma, and second plasma gas comprises hydrogen. Metal is filled in the opening. According to the interconnection structure forming method, gas containing the carbon monoxide is used for processing the opening, most fluorine-containing polymer is eliminated, contact resistance in a metal interconnection structure is reduced, then the gas containing the hydrogen is used for processing the opening, reduction of copper oxide exposed outside is achieved, the residual fluorine-containing polymer is further eliminated, adhesion performance of metallic copper and interface materials is improved, and electron transfer / stress transfer effect of the metal interconnection structure is improved.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing technology, in particular to a method for forming an interconnection structure. Background technique [0002] Currently, in a back-end-of-line (BEOL) process of a semiconductor device, after the semiconductor device layer is formed, a metal interconnection layer needs to be formed on the semiconductor device layer to lead out electrodes. Forming the metal interconnection layer usually includes making trenches in the insulating material layer, and then forming metal in the trenches to form the metal interconnection lines. [0003] With the continuous development of integrated circuit manufacturing technology, the number of devices per unit area is also increasing, and the interconnection problem has become one of the main factors affecting the improvement of circuit performance. The increase in the aspect ratio of the metal interconnection leads to an increase in the parasitic capacitanc...

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Problems solved by technology

[0005] In the process of etching to form openings, the etching reaction gas usually used will contain CF 4 、CF 8 、C 5 f 8 、C 4 f 6 、CHF 3 One of the gases, after the etching is completed, due to the reaction of the etching gas with the material to be etched, a high molecular polymer, such as a fluorine-containing polymer, is usually formed on the bottom of the opening or on the surface of the side wall. It must be removed after etching, otherwise it will become a source of particles and pollutants that increase the defect density of the product surface, damage device performance, and affect device yield and reliability

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