Method of forming an integrated circuit structure

Abstract

A method of forming an integrated circuit structure includes forming a copper-containing seed layer on a wafer, and performing a descum step on an exposed surface of the copper-containing seed layer. The descum step is performed using a process gas including fluorine and oxygen. A reduction / purge step is then performed on the exposed surface of the copper-containing seed layer using a nitrogen-containing gas. A copper-containing layer is plated on the copper-containing seed layer.

Description

technical field [0001] The invention relates to a method for forming an integrated circuit structure, in particular to a process for forming bumps. Background technique [0002] When forming a semiconductor chip, integrated circuit elements, such as transistors, are first formed on the surface of the semiconductor substrate of the chip, and then interconnection structures are formed on the integrated circuit elements. Next, bumps are formed on the surface of the chip to facilitate the use of integrated circuit elements. [0003] In a typical bump forming process, an under-bump metallurgy (UBM) is formed first, and then a bump is formed on the under-bump metallurgy. Forming the UBM layer may include forming a copper seed layer, forming a mask on the copper seed layer and patterning the mask such that a portion of the copper seed layer is exposed through openings in the mask. Then, an electroplating step is performed to electroplate a thick copper layer on the exposed portio...

AI Technical Summary

Problems solved by technology

During subsequent processes, the bumps may delaminate due to poor adhesion between the copper seed layer and the electroplated copper

The above challenges result in lower bump yields and higher manufacturing costs, as well as poorer bump reliability

Images