Method for bonding metallization modification on semiconductor unpacked chip

Abstract

The invention discloses a method for bonding metallization modification on a semiconductor unpacked chip. The method comprises the following steps: putting a deoiled semiconductor unpacked chip surface or a wafer into a mixed solution of sulfuric acid and hydrogen peroxide, performing reaction for 60-90 seconds at 30-40 DEG C, dehydrating, performing primary zinc activation, performing acid corrosion, performing secondary zinc activation, performing deposition on the surface of the unpacked chip or the wafer after secondary zinc activation so as to form an Ni layer; depositing a Pd layer on the Ni layer; depositing an Au layer on the Pd layer. By using a chemical nickel and palladium plating gold leaching process, three layers of metallization layers of nickel, palladium and gold compatible with gold thread bonding are prepared on the surface of the deoiled semiconductor unpacked chip, the adhesion strength and the stability of a membrane layer meet application requirements of packaging processes, various electric parameters of the modified chip are not greatly different from those before modification, and gold thread bonding implemented on the surface of the modified nickel, palladium and gold layer can meet high-temperature environment application and reliability requirements of long-service life application of devices.

Description

technical field [0001] The invention belongs to the field of semiconductor packaging, and in particular relates to a method for realizing bonding metallization modification on a bare semiconductor chip. Background technique [0002] At present, the metallization layer on the surface of semiconductor chips is mostly made of aluminum and aluminum alloy materials, while semiconductor packaging structures such as integrated circuits and hybrid integrated circuits mainly use gold wire thermosonic bonding interconnection technology, which leads to the surface of bare chips being damaged after bonding. A gold-aluminum compound alloy layer is formed. [0003] Existing research and reliability test results show that under the temperature condition of 300°C and above, the performance of the bonding point will decay in a very short time, and in severe cases, the bonding point will fall off and cause the device to fail. . The main reason for this phenomenon is that the atomic diffusio...

AI Technical Summary

Problems solved by technology

These metal compounds are not inherently detrimental to device performance, but their presence can signal a less reliable solder joint

This is because these gold-aluminum intermetallic compounds are brittle phases, and their mechanical properties and thermal properties are significantly different from those of Au and Al. They are easy to crack under external stress, which leads to open circuits of solder joints and failure of electronic devices.

[0004] In view of the above situation, the ubiquitous heterogeneous bonding process in semiconductor packaging devices has been difficult to meet the quality and reliability requirements of high-reliability components and high-temperature application components