Abstract

Hydrophilicity of the aluminium thin film’s surface is one of the imperative surface characteristics needed for metal pad bonding process in microelectronic circuitries. In this paper, we present a study on the influence of argon plasma exposure on the surface properties of sputter-deposited aluminium thin film layer. The exposure of aluminium thin film layer in argon plasma at atmospheric pressure and low pressure are carried out and compared. The water contact angle and surface topology of the aluminium’s surface are inspected. The aluminium–gold metal–metal ohmic contact resistance and the aluminium thin film sheet resistivity are measured. Argon plasma has modified the originally hydrophobic aluminium’s surface into hydrophilic profile, which may be related to its increase of surface energy. Higher/smaller thin film surface roughness has been measured from the low-pressure/atmospheric-pressure argon plasma exposure that produces thin film with higher (9.64 Ω)/smaller (6.78 Ω) contact resistivity compared to the unexposed aluminium thin film layer (7.85 Ω). The argon plasma exposure treatment on the aluminium thin film has generally improved its surface properties, inducing hydrophilicity surface profile for the aluminium metal pad. The conducted treatment at the atmospheric pressure level specifically helps to reduce the surface roughness and increase the thin film layer conductivity.

中文翻译：

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通过低压和常压氩等离子暴露进行铝薄膜表面改性

摘要

铝薄膜表面的亲水性是微电子电路中金属焊盘键合工艺所必需的表面特性之一。在本文中，我们研究了氩等离子体暴露对溅射沉积铝薄膜层表面性质的影响。对铝薄膜层在大气压和低压氩等离子体中的曝光进行了比较。检查铝表面的水接触角和表面拓扑结构。测量铝-金金属-金属欧姆接触电阻和铝薄膜片电阻率。氩等离子体将原本疏水的铝表面改造成亲水分布，这可能与其表面能的增加有关。更高/更小的薄膜表面粗糙度是通过低压/大气压氩等离子体曝光测量的，与未曝光的铝薄膜层（7.85 Ω）。铝薄膜上的氩等离子体暴露处理总体上改善了其表面性质，使铝金属焊盘具有亲水性表面轮廓。在大气压水平下进行的处理特别有助于降低表面粗糙度并增加薄膜层的导电性。铝薄膜上的氩等离子体暴露处理总体上改善了其表面性质，使铝金属焊盘具有亲水性表面轮廓。在大气压水平下进行的处理特别有助于降低表面粗糙度并增加薄膜层的导电性。铝薄膜上的氩等离子体暴露处理总体上改善了其表面性质，使铝金属焊盘具有亲水性表面轮廓。在大气压水平下进行的处理特别有助于降低表面粗糙度并增加薄膜层的导电性。