A kind of manufacturing method of aluminum welding pad

Abstract

The invention discloses an aluminum bonding pad manufacturing method. The method includes: depositing an etching barrier layer and a passivation protecting layer on a semiconductor substrate comprising a metal interconnection line in sequence; forming trenches in the passivation protecting layer and the etching barrier mater via photoetching and etching to expose the interconnection line on the semiconductor substrate; depositing aluminum metal on the surface of the passivation protecting layer inside and outside the trench to form an aluminum layer comprising recesses and protrusions, and enabling the bottom of the aluminum layer to contact with interconnection metal; adopting a pulse laser bombardment method to etch the aluminum layer so as to modify the morphology of the aluminum layer; depositing metallic aluminum on the aluminum layer to form a flat aluminum layer; and forming an aluminum bonding pad via photoetching and etching. The method has the advantages that the protrusions can be removed, depth of the recesses can be decreased, the aluminum bonding pad is more compact and is modified, a flat aluminum bonding pad layer is formed, residuals of etching reaction by-products are prevented, probability of corrosion to the aluminum bonding pad is lowered, and quality and reliability of the aluminum bonding pad are improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for manufacturing an aluminum pad. Background technique [0002] In the semiconductor integrated circuit industry, high-performance integrated circuit chips require defect-free and highly reliable electrical connections. The aluminum pad layer in the interconnection process is the outermost interconnection of the semiconductor integrated chip, directly in contact with the external environment, and is a bridge connecting the chip with the peripheral circuit, which plays a very important role. Due to direct contact with the external environment, if the quality of the aluminum pad is poor, it is easy to cause defects and failures in the process device. For example, in the packaging process, a large part of the failure comes from desoldering or excessive contact resistance. Since the material of the aluminum pad is metal aluminum, the chemical property i...

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Problems solved by technology

Moreover, when the temperature is higher, the aluminum layer is in an active state with higher energy, and it is easy to produce whisker-shaped defects. This defect has a greater impact on the subsequent process and is also a fatal defect. Therefore, by increasing the temperature to enhance the effect of gap filling ability is limited

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