Electroless gold-plating method for microsize line of substrate

Abstract

The invention discloses an electroless gold-plating method for microsize line of a substrate. The method comprises the following steps: firstly, clearing residual organic matters on the substrate, and infiltrating the substrate to increase the wetting degree of the substrate surface; and the method is characterized in that: when the substrate to be plated is placed in a gold-plating bath, gold ions in the gold-plating bath are activated through regulation of temperature and concentration, so that the gold ions are positively deposited on the surface of the metal line to be plated to form a gold-plating layer. Thus, in the method, an additional isolation layer arranging step is not required, namely the gold-plating layer with uniform thickness is formed through a chemical reaction, especially cyanide is not added in the gold-plating bath, so that toxicity is low; and carboxy compounds and salts of carboxy compounds in the gold-plating bath are utilized as the deposition stabilizers of the gold-plating bath, so that the gold ion has high safety, high deposition rate and high content of adhesive gold, thus the method is specially suitable for the substrate with the microsize line.

Description

technical field [0001] The invention relates to an electroless gold plating method, in particular to a method especially suitable for plating a metal layer with a uniform thickness on micro-sized circuits. Background technique [0002] Due to the advancement of integrated circuit manufacturing technology, manufacturing circuits with a size below 0.25 microns is the mainstream of the current metallization process. As the circuit size shrinks day by day, how to efficiently form conductive substances on the substrate with micro-sized circuits is an important key to development. [0003] The electroplating process is a technology that efficiently fills conductive substances in circuits with tiny dimensions. Electroplating is to immerse the workpiece to be plated in an ionic solution containing the electroplating metal, so that the power supply and the cathode and anode in the electroplating tank (consumed Sexual or non-consumable) electrical connection, at the same time, the el...

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Problems solved by technology

[0006] However, the disadvantage of the prior art is that the way of electroplating gold plating is very easy to form a gold plating layer with uneven thickness, which is caused by the influence of high and low current regions in electroplating, resulting in uneven thickness. In addition, the gold plating bath must be preset in advance during the gold plating operation. Isolation layer, and then remove the isolation layer, in addition to causing trouble and inconvenience to the gold plating operation, but also increase the cost of materials and prolong the processing time of the entire process, so it is necessary to rely on the interaction of chemical components, which can be applied to the tiny surface of the substrate Method for forming gold-plated layer with uniform thickness on dimensional lines

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