Electroless Copper Plating Solutions for Microvia Filling

Abstract

A chemical copper plating solution for micropore filling. 1 L of the chemical copper plating solution comprises 5-20 g of copper sulfate pentahydrate, 10-50 g of disodium ethylene diamine tetraacetate, 1.0-1.5 g of formaldehyde or glyoxylic acid, 0.001-0.02 g of mercapto heterocyclic compounds, 0.02-0.04 g of polyether with an average molecular weight of 3650, 1.5-3.5 g of NaOH, and the balance of distilled water; the mercapto heterocyclic compounds are 2-mercapto benzimidazole, 2- mercapto benzoxazole, 1-phenyl-5-mercapto-tetrazole or 2-mercapto benzothiazole. By simultaneously adding mercapto heterocyclic compounds and polyether with an average molecular weight of 3650 into the chemical copper plating solution, the invention realizes no cavity, no gap of micropores, and perfect chemicalcopper filling; the chemical copper plating solution is stable; and the deposited copper film has good quality.

Description

technical field [0001] The invention belongs to the technical field of manufacturing ultra-large-scale integrated circuit copper interconnection wires and interconnection wires between storage points of semiconductor chips, and in particular relates to the synergistic effect of thiol-containing heterocyclic compounds and polyether to realize super chemical filling of micropores. Background technique [0002] Metallic copper has low resistivity and high resistance to electromigration, and is widely used in copper interconnects of ultra-large-scale integration (ULSI) circuits. As the semiconductor silicon chip at the core of the microsystem, the storage density continues to increase, the interconnection line width between storage points becomes narrower and narrower, and it becomes more and more difficult to fill with electroplating copper. Therefore, chemical filling technology came into being. The essence of perfect chemical filling is to fill copper without voids and gaps ...

AI Technical Summary

Problems solved by technology

At present, micropores are generally filled by adding a single inhibitor to suppress copper deposition on the surface, but this method cannot completely fill micropores with a high aspect ratio.

Wang Zenglin and others found that adding sodium polydithiodipropane sulfonate and polyethylene glycol with a molecular weight of 4000 for copper electroplating can achieve chemical copper filling, but the stability of the plating solution is poor

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