Copper-interconnection production method for ultra-low dielectric constant film

Abstract

The invention relates to a copper-interconnection production method for an ultra-low dielectric constant film. The production method comprises the following steps of: covering a low dielectric constant protection film on the ultra-low dielectric constant film; then photoetching and etching to form a through hole and / or a trench penetrating through the low dielectric constant protection film and the ultra-low dielectric constant film; sputtering and depositing a metal barrier layer and a copper seed crystal layer in the through hole and / or the trench; and filling and depositing copper by adopting an electroplating process to form a copper interconnected layer. Due to the adoption of the low dielectric constant protection film, the defect of a porous ultra-low dielectric constant film generated in the chemical mechanical polishing is reduced, the adherence force of the low dielectric constant protection film and the next copper-interconnection etching stop layer is enhanced, hot mechanical failure caused by induced stress in the subsequent package is avoided and the reliability is simultaneously improved.

Description

technical field [0001] The invention relates to semiconductor technology, in particular to a manufacturing method for ultra-low dielectric constant film copper interconnection. Background technique [0002] With the continuous advancement of VLSI process technology, the feature size of semiconductor devices has been continuously reduced, and the chip area has continued to increase. The delay time of interconnection leads can be compared with the device gate delay time. People are faced with the problem of how to overcome the significant increase in RC (R refers to resistance, C refers to capacitance) delay due to the rapid increase in connection length. In particular, due to the increasing influence of the capacitance between metal wiring lines, the performance of the device is greatly reduced, which has become a key restrictive factor for the further development of the semiconductor industry. In order to reduce the RC delay caused by interconnection, various measures have ...

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Problems solved by technology

However, the shortcomings of ultra-low dielectric constant materials with porous and loose structures are that they are fragile and easily contaminated by impurities, which makes it difficult to combine with other layers in the subsequent manufacturing process, and the shape, damage, and reliability of the interconnection layer are not easy. Control; because the hardness and modulus of the ultra-low dielectric constant film are smaller than that of SiO deposited by traditional plasma chemical vapor deposition 2 Medium, ultra-low dielectric constant film has many defects after chemical mechanical polishing, such as metal, grinding liquid filter residue, surface scratches; due to the hydrophobicity of ultra-low dielectric constant film, resulting in The medium cleaning effect is not ideal; the adhesion force between the porous ultra-low dielectric constant film and the upper etching stop layer is not enough, and the dielectric layer delamination between the ultra-low dielectric constant film and the etching stop layer is prone to occur, resulting in circuit breakage; at the same time Induced stress in subsequent packaging is prone to thermomechanical failure

Therefore, in order to overcome the above defects, an ultra-low dielectric constant film is covered with a layer based on SiO 2 dielectric protective film, but the SiO-based 2 The increase of the protective film of the dielectric brings about the increase of the interlayer capacitance and the increase of the effective dielectric constant.

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