Manufacturing method of copper-copper bonding salient points

Abstract

The invention provides a manufacturing method of copper-copper bonding salient points. The surface roughness of a copper cylinder is effectively reduced, the surface evenness of the micro salient points is improved, meanwhile, the consistency of the heights of the micro salient points in different areas of a wafer is guaranteed, and the requirements of a copper-copper bonding technology for the surface smoothness are met. The manufacturing method is characterized by including the following steps: (1) manufacturing an adhesion layer and a seed layer on the surface of the wafer, (2) depositing a copper layer on the surface of the wafer, (3) processing the copper layer on the surface of the wafer, and improving the surface roughness and the surface evenness of copper; (4) imaging the copper layer with a photolithography technique, (5) removing copper outside the positions of the micro salient points, and forming micro salient point structures on the wafer, (6) removing adhesion layer materials outside micro salient point areas of the surface of the wafer, and forming electrical isolation micro salient point structures, and (7) removing photoresist on the surface of the wafer, and obtaining the micro salient point structures with the even heights and the flat and smooth surfaces.

Description

technical field [0001] The invention relates to the technical field of microelectronic packaging, in particular to a method for manufacturing copper-copper bonding bumps. Background technique [0002] The current micro-bump manufacturing process uses photoresist to define the electroplating area after the seed layer is manufactured. Limited by the height of the micro-bumps, the thickness of the photoresist is relatively large, which leads to the insufficient capability of the traditional micro-bump manufacturing process in the production of small-sized micro-bumps. In addition, the copper-copper bonding process has strict requirements on the flatness of the bonding interface, and the electroplating process cannot meet its requirements. First of all, the surface roughness of the copper pillars produced by the electroplating process is relatively large, which cannot meet the requirements of copper-copper bonding for surface flatness; secondly, the flatness of the micro-bumps ...

AI Technical Summary

Problems solved by technology

Limited by the height of the micro-bumps, the thickness of the photoresist is relatively large, which leads to the insufficient capability of the traditional micro-bump manufacturing process in the production of small-sized micro-bumps

In addition, the copper-copper bonding process has almost strict requirements on the flatness of the bonding interface, and the electroplating process cannot meet its requirements

First of all, the surface roughness of the copper pillars produced by the electroplating process is relatively large, which cannot meet the requirements of copper-copper bonding for surface flatness; secondly, the flatness of the micro-bumps produced by the electroplating process is poor, especially when there are steps in the lower layer , it is also difficult to ensure the flatness of the surface of the micro-bump surface; thirdly, using the micro-bump technology of the traditional process, the height of the micro-bump in different regions of the wafer will have a large difference, which will affect the bonding quality

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